treewide: rename nix::fmt to nix::boostfmt

This was mostly automated with clangd, but a couple dozen stragglers or
so that weren't caught by clangd were done by hand.

Change-Id: I1d9551690d4b36cd9ff92517184586c341bad92a

src/build-remote/build-remote.cc

@@ -48,7 +48,7 @@ static std::string makeLockFilename(const std::string & storeUri) {
 
 static AutoCloseFD openSlotLock(const Machine & m, uint64_t slot)
 {
-    return openLockFile(fmt("%s/%s-%d", currentLoad, makeLockFilename(m.storeUri), slot), true);
+    return openLockFile(boostfmt("%s/%s-%d", currentLoad, makeLockFilename(m.storeUri), slot), true);
 }
 
 static bool allSupportedLocally(Store & store, const std::set<std::string>& requiredFeatures) {
@@ -245,7 +245,7 @@ static int main_build_remote(int argc, char * * argv)
 
                 try {
 
-                    Activity act(*logger, lvlTalkative, actUnknown, fmt("connecting to '%s'", bestMachine->storeUri));
+                    Activity act(*logger, lvlTalkative, actUnknown, boostfmt("connecting to '%s'", bestMachine->storeUri));
 
                     sshStore = bestMachine->openStore();
                     sshStore->connect();
@@ -279,7 +279,7 @@ connected:
         AutoCloseFD uploadLock = openLockFile(lockFileName, true);
 
         {
-            Activity act(*logger, lvlTalkative, actUnknown, fmt("waiting for the upload lock to '%s'", storeUri));
+            Activity act(*logger, lvlTalkative, actUnknown, boostfmt("waiting for the upload lock to '%s'", storeUri));
 
             auto old = signal(SIGALRM, handleAlarm);
             alarm(15 * 60);
@@ -292,7 +292,7 @@ connected:
         auto substitute = settings.buildersUseSubstitutes ? Substitute : NoSubstitute;
 
         {
-            Activity act(*logger, lvlTalkative, actUnknown, fmt("copying dependencies to '%s'", storeUri));
+            Activity act(*logger, lvlTalkative, actUnknown, boostfmt("copying dependencies to '%s'", storeUri));
             copyPaths(*store, *sshStore, store->parseStorePathSet(inputs), NoRepair, NoCheckSigs, substitute);
         }
 
@@ -373,7 +373,7 @@ connected:
         }
 
         if (!missingPaths.empty()) {
-            Activity act(*logger, lvlTalkative, actUnknown, fmt("copying outputs from '%s'", storeUri));
+            Activity act(*logger, lvlTalkative, actUnknown, boostfmt("copying outputs from '%s'", storeUri));
             if (auto localStore = store.dynamic_pointer_cast<LocalStore>())
                 for (auto & path : missingPaths)
                     localStore->locksHeld.insert(store->printStorePath(path)); /* FIXME: ugly */

src/libcmd/cmd-profiles.cc

@@ -43,7 +43,7 @@ bool ProfileElementSource::operator<(const ProfileElementSource & other) const
 
 std::string ProfileElementSource::to_string() const
 {
-    return fmt("%s#%s%s", originalRef, attrPath, outputs.to_string());
+    return boostfmt("%s#%s%s", originalRef, attrPath, outputs.to_string());
 }
 
 std::string ProfileElement::identifier() const

src/libcmd/command.cc

@@ -305,7 +305,7 @@ void MixEnvironment::setEnviron() {
 
         for (const auto & var : keep) {
             auto val = getenv(var.c_str());
-            if (val) stringsEnv.emplace_back(fmt("%s=%s", var.c_str(), val));
+            if (val) stringsEnv.emplace_back(boostfmt("%s=%s", var.c_str(), val));
         }
 
         vectorEnv = stringsToCharPtrs(stringsEnv);

src/libcmd/editor-for.cc

@@ -16,7 +16,7 @@ Strings editorFor(const SourcePath & file, uint32_t line)
         editor.find("nano") != std::string::npos ||
         editor.find("vim") != std::string::npos ||
         editor.find("kak") != std::string::npos))
-        args.push_back(fmt("+%d", line));
+        args.push_back(boostfmt("+%d", line));
     args.push_back(path->abs());
     return args;
 }

src/libcmd/installable-attr-path.cc

@@ -50,7 +50,7 @@ DerivedPathsWithInfo InstallableAttrPath::toDerivedPaths()
     if (std::optional derivedPathWithInfo = trySinglePathToDerivedPaths(
         *v,
         pos,
-        fmt("while evaluating the attribute '%s'", attrPath)))
+        boostfmt("while evaluating the attribute '%s'", attrPath)))
     {
         return { *derivedPathWithInfo };
     }

src/libcmd/installable-flake.cc

@@ -87,7 +87,7 @@ InstallableFlake::InstallableFlake(
 
 DerivedPathsWithInfo InstallableFlake::toDerivedPaths()
 {
-    Activity act(*logger, lvlTalkative, actUnknown, fmt("evaluating derivation '%s'", what()));
+    Activity act(*logger, lvlTalkative, actUnknown, boostfmt("evaluating derivation '%s'", what()));
 
     auto attr = getCursor(*state);
 
@@ -101,7 +101,7 @@ DerivedPathsWithInfo InstallableFlake::toDerivedPaths()
         if (std::optional derivedPathWithInfo = trySinglePathToDerivedPaths(
             v,
             noPos,
-            fmt("while evaluating the flake output attribute '%s'", attrPath)))
+            boostfmt("while evaluating the flake output attribute '%s'", attrPath)))
         {
             return { *derivedPathWithInfo };
         } else {

src/libexpr/eval.cc

@@ -158,9 +158,9 @@ std::string showType(const Value & v)
     switch (v.internalType) {
         case tString: return v.string.context ? "a string with context" : "a string";
         case tPrimOp:
-            return fmt("the built-in function '%s'", std::string(v.primOp->name));
+            return boostfmt("the built-in function '%s'", std::string(v.primOp->name));
         case tPrimOpApp:
-            return fmt("the partially applied built-in function '%s'", std::string(getPrimOp(v)->primOp->name));
+            return boostfmt("the partially applied built-in function '%s'", std::string(getPrimOp(v)->primOp->name));
         case tExternal: return v.external->showType();
         case tThunk: return v.isBlackhole() ? "a black hole" : "a thunk";
         case tApp: return "a function application";

src/libexpr/flake/config.cc

@@ -43,7 +43,7 @@ void ConfigFile::apply()
         if (auto* s = std::get_if<std::string>(&value))
             valueS = *s;
         else if (auto* n = std::get_if<int64_t>(&value))
-            valueS = fmt("%d", *n);
+            valueS = boostfmt("%d", *n);
         else if (auto* b = std::get_if<Explicit<bool>>(&value))
             valueS = b->t ? "true" : "false";
         else if (auto ss = std::get_if<std::vector<std::string>>(&value))
@@ -66,12 +66,12 @@ void ConfigFile::apply()
                     printInfo("Using saved setting for '%s = %s' from ~/.local/share/nix/trusted-settings.json.", name, valueS);
                 } else {
                     // FIXME: filter ANSI escapes, newlines, \r, etc.
-                    if (std::tolower(logger->ask(fmt("Do you want to allow configuration setting '%s' to be set to '" ANSI_RED "%s" ANSI_NORMAL "' (y/N)? This may allow the flake to gain root, see the nix.conf manual page.", name, valueS)).value_or('n')) == 'y') {
+                    if (std::tolower(logger->ask(boostfmt("Do you want to allow configuration setting '%s' to be set to '" ANSI_RED "%s" ANSI_NORMAL "' (y/N)? This may allow the flake to gain root, see the nix.conf manual page.", name, valueS)).value_or('n')) == 'y') {
                         trusted = true;
                     } else {
                         warn("you can set '%s' to '%b' to automatically reject configuration options supplied by flakes", "accept-flake-config", false);
                     }
-                    if (std::tolower(logger->ask(fmt("do you want to permanently mark this value as %s (y/N)?",  trusted ? "trusted": "untrusted" )).value_or('n')) == 'y') {
+                    if (std::tolower(logger->ask(boostfmt("do you want to permanently mark this value as %s (y/N)?",  trusted ? "trusted": "untrusted" )).value_or('n')) == 'y') {
                         trustedList[name][valueS] = trusted;
                         writeTrustedList(trustedList);
                     }

src/libexpr/flake/flake.cc

@@ -664,7 +664,7 @@ LockedFlake lockFlake(
                         if (!lockFlags.updateLockFile)
                             throw Error("flake '%s' requires lock file changes but they're not allowed due to '--no-update-lock-file'", topRef);
 
-                        auto newLockFileS = fmt("%s\n", newLockFile);
+                        auto newLockFileS = boostfmt("%s\n", newLockFile);
 
                         if (lockFlags.outputLockFilePath) {
                             if (lockFlags.commitLockFile)
@@ -693,7 +693,7 @@ LockedFlake lockFlake(
                                 cm = fetchSettings.commitLockFileSummary.get();
 
                                 if (cm == "") {
-                                    cm = fmt("%s: %s", relPath, lockFileExists ? "Update" : "Add");
+                                    cm = boostfmt("%s: %s", relPath, lockFileExists ? "Update" : "Add");
                                 }
 
                                 cm += "\n\nFlake lock file updates:\n\n";
@@ -925,7 +925,7 @@ Fingerprint LockedFlake::getFingerprint() const
     // and we haven't changed it, then it's sufficient to use
     // flake.sourceInfo.storePath for the fingerprint.
     return hashString(htSHA256,
-        fmt("%s;%s;%d;%d;%s",
+        boostfmt("%s;%s;%d;%d;%s",
             flake.sourceInfo->storePath.to_string(),
             flake.lockedRef.subdir,
             flake.lockedRef.input.getRevCount().value_or(0),

src/libexpr/flake/lockfile.cc

@@ -132,7 +132,7 @@ nlohmann::json LockFile::toJSON() const
 
         if (!keys.insert(key).second) {
             for (int n = 2; ; ++n) {
-                auto k = fmt("%s_%d", key, n);
+                auto k = boostfmt("%s_%d", key, n);
                 if (keys.insert(k).second) {
                     key = k;
                     break;
@@ -199,7 +199,7 @@ std::ostream & operator <<(std::ostream & stream, const LockFile & lockFile)
 void LockFile::write(const Path & path) const
 {
     createDirs(dirOf(path));
-    writeFile(path, fmt("%s\n", *this));
+    writeFile(path, boostfmt("%s\n", *this));
 }
 
 std::optional<FlakeRef> LockFile::isUnlocked() const
@@ -279,10 +279,10 @@ std::map<InputPath, Node::Edge> LockFile::getAllInputs() const
 
 static std::string describe(const FlakeRef & flakeRef)
 {
-    auto s = fmt("'%s'", flakeRef.to_string());
+    auto s = boostfmt("'%s'", flakeRef.to_string());
 
     if (auto lastModified = flakeRef.input.getLastModified())
-        s += fmt(" (%s)", std::put_time(std::gmtime(&*lastModified), "%Y-%m-%d"));
+        s += boostfmt(" (%s)", std::put_time(std::gmtime(&*lastModified), "%Y-%m-%d"));
 
     return s;
 }
@@ -292,7 +292,7 @@ std::ostream & operator <<(std::ostream & stream, const Node::Edge & edge)
     if (auto node = std::get_if<0>(&edge))
         stream << describe((*node)->lockedRef);
     else if (auto follows = std::get_if<1>(&edge))
-        stream << fmt("follows '%s'", printInputPath(*follows));
+        stream << boostfmt("follows '%s'", printInputPath(*follows));
     return stream;
 }
 
@@ -318,15 +318,15 @@ std::string LockFile::diff(const LockFile & oldLocks, const LockFile & newLocks)
 
     while (i != oldFlat.end() || j != newFlat.end()) {
         if (j != newFlat.end() && (i == oldFlat.end() || i->first > j->first)) {
-            res += fmt("• " ANSI_GREEN "Added input '%s':" ANSI_NORMAL "\n    %s\n",
+            res += boostfmt("• " ANSI_GREEN "Added input '%s':" ANSI_NORMAL "\n    %s\n",
                 printInputPath(j->first), j->second);
             ++j;
         } else if (i != oldFlat.end() && (j == newFlat.end() || i->first < j->first)) {
-            res += fmt("• " ANSI_RED "Removed input '%s'" ANSI_NORMAL "\n", printInputPath(i->first));
+            res += boostfmt("• " ANSI_RED "Removed input '%s'" ANSI_NORMAL "\n", printInputPath(i->first));
             ++i;
         } else {
             if (!equals(i->second, j->second)) {
-                res += fmt("• " ANSI_BOLD "Updated input '%s':" ANSI_NORMAL "\n    %s\n  → %s\n",
+                res += boostfmt("• " ANSI_BOLD "Updated input '%s':" ANSI_NORMAL "\n    %s\n  → %s\n",
                     printInputPath(i->first),
                     i->second,
                     j->second);

src/libexpr/get-drvs.cc

@@ -392,7 +392,7 @@ static void getDerivations(EvalState & state, Value & vIn,
         // NOTE we can't really deduplicate here because small lists don't have stable addresses
         // and can cause spurious duplicate detections due to v being on the stack.
         for (auto [n, elem] : enumerate(v.listItems())) {
-            std::string pathPrefix2 = addToPath(pathPrefix, fmt("%d", n));
+            std::string pathPrefix2 = addToPath(pathPrefix, boostfmt("%d", n));
             if (getDerivation(state, *elem, pathPrefix2, drvs, ignoreAssertionFailures))
                 getDerivations(state, *elem, pathPrefix2, autoArgs, drvs, done, ignoreAssertionFailures);
         }

src/libexpr/nixexpr.cc

@@ -577,7 +577,7 @@ std::string ExprLambda::showNamePos(const EvalState & state) const
     std::string id(name
         ? concatStrings("'", state.symbols[name], "'")
         : "anonymous function");
-    return fmt("%1% at %2%", id, state.positions[pos]);
+    return boostfmt("%1% at %2%", id, state.positions[pos]);
 }
 
 

src/libexpr/parser/parser.cc

@@ -81,7 +81,7 @@ struct Control : p::must_if<SyntaxErrors>::control<Rule>
         if (in.empty()) {
             std::string expected;
             if constexpr (constexpr auto msg = error_message<Rule>)
-                expected = fmt(", %s", msg);
+                expected = boostfmt(", %s", msg);
             throw p::parse_error("unexpected end of file" + expected, in);
         }
         p::must_if<SyntaxErrors>::control<Rule>::raise(in, st...);

src/libexpr/primops/fetchTree.cc

@@ -65,7 +65,7 @@ void emitTreeAttrs(
     if (auto lastModified = input.getLastModified()) {
         attrs.alloc("lastModified").mkInt(*lastModified);
         attrs.alloc("lastModifiedDate").mkString(
-            fmt("%s", std::put_time(std::gmtime(&*lastModified), "%Y%m%d%H%M%S")));
+            boostfmt("%s", std::put_time(std::gmtime(&*lastModified), "%Y%m%d%H%M%S")));
     }
 
     v.mkAttrs(attrs);

src/libexpr/value-to-xml.cc

@@ -23,8 +23,8 @@ static void posToXML(EvalState & state, XMLAttrs & xmlAttrs, const Pos & pos)
 {
     if (auto path = std::get_if<SourcePath>(&pos.origin))
         xmlAttrs["path"] = path->path.abs();
-    xmlAttrs["line"] = fmt("%1%", pos.line);
+    xmlAttrs["line"] = boostfmt("%1%", pos.line);
-    xmlAttrs["column"] = fmt("%1%", pos.column);
+    xmlAttrs["column"] = boostfmt("%1%", pos.column);
 }
 
 
@@ -61,7 +61,7 @@ static void printValueAsXML(EvalState & state, bool strict, bool location,
     switch (v.type()) {
 
         case nInt:
-            doc.writeEmptyElement("int", singletonAttrs("value", fmt("%1%", v.integer)));
+            doc.writeEmptyElement("int", singletonAttrs("value", boostfmt("%1%", v.integer)));
             break;
 
         case nBool:
@@ -153,7 +153,7 @@ static void printValueAsXML(EvalState & state, bool strict, bool location,
             break;
 
         case nFloat:
-            doc.writeEmptyElement("float", singletonAttrs("value", fmt("%1%", v.fpoint)));
+            doc.writeEmptyElement("float", singletonAttrs("value", boostfmt("%1%", v.fpoint)));
             break;
 
         case nThunk:

src/libfetchers/attrs.cc

@@ -94,7 +94,7 @@ std::map<std::string, std::string> attrsToQuery(const Attrs & attrs)
     std::map<std::string, std::string> query;
     for (auto & attr : attrs) {
         if (auto v = std::get_if<uint64_t>(&attr.second)) {
-            query.insert_or_assign(attr.first, fmt("%d", *v));
+            query.insert_or_assign(attr.first, boostfmt("%d", *v));
         } else if (auto v = std::get_if<std::string>(&attr.second)) {
             query.insert_or_assign(attr.first, *v);
         } else if (auto v = std::get_if<Explicit<bool>>(&attr.second)) {

src/libfetchers/fetch-to-store.cc

@@ -12,7 +12,7 @@ StorePath fetchToStore(
     PathFilter * filter,
     RepairFlag repair)
 {
-    Activity act(*logger, lvlChatty, actUnknown, fmt("copying '%s' to the store", path));
+    Activity act(*logger, lvlChatty, actUnknown, boostfmt("copying '%s' to the store", path));
 
     auto filter2 = filter ? *filter : defaultPathFilter;
 

src/libfetchers/git.cc

@@ -576,7 +576,7 @@ struct GitInputScheme : InputScheme
             }
 
             if (doFetch) {
-                Activity act(*logger, lvlTalkative, actUnknown, fmt("fetching Git repository '%s'", actualUrl));
+                Activity act(*logger, lvlTalkative, actUnknown, boostfmt("fetching Git repository '%s'", actualUrl));
 
                 // FIXME: git stderr messes up our progress indicator, so
                 // we're using --quiet for now. Should process its stderr.
@@ -589,7 +589,7 @@ struct GitInputScheme : InputScheme
                             : ref == "HEAD"
                                 ? *ref
                                 : "refs/heads/" + *ref;
-                    runProgram("git", true, { "-C", repoDir, "--git-dir", gitDir, "fetch", "--quiet", "--force", "--", actualUrl, fmt("%s:%s", fetchRef, fetchRef) }, true);
+                    runProgram("git", true, { "-C", repoDir, "--git-dir", gitDir, "fetch", "--quiet", "--force", "--", actualUrl, boostfmt("%s:%s", fetchRef, fetchRef) }, true);
                 } catch (Error & e) {
                     if (!pathExists(localRefFile)) throw;
                     warn("could not update local clone of Git repository '%s'; continuing with the most recent version", actualUrl);
@@ -654,7 +654,7 @@ struct GitInputScheme : InputScheme
                 // TODO: repoDir might lack the ref (it only checks if rev
                 // exists, see FIXME above) so use a big hammer and fetch
                 // everything to ensure we get the rev.
-                Activity act(*logger, lvlTalkative, actUnknown, fmt("making temporary clone of '%s'", repoDir));
+                Activity act(*logger, lvlTalkative, actUnknown, boostfmt("making temporary clone of '%s'", repoDir));
                 runProgram("git", true, { "-C", tmpDir, "fetch", "--quiet", "--force",
                         "--update-head-ok", "--", repoDir, "refs/*:refs/*" }, true);
             }
@@ -677,12 +677,12 @@ struct GitInputScheme : InputScheme
                source repo if it exists. */
             auto modulesPath = repoDir + "/" + gitDir + "/modules";
             if (pathExists(modulesPath)) {
-                Activity act(*logger, lvlTalkative, actUnknown, fmt("copying submodules of '%s'", actualUrl));
+                Activity act(*logger, lvlTalkative, actUnknown, boostfmt("copying submodules of '%s'", actualUrl));
                 runProgram("cp", true, { "-R", "--", modulesPath, tmpGitDir + "/modules" });
             }
 
             {
-                Activity act(*logger, lvlTalkative, actUnknown, fmt("fetching submodules of '%s'", actualUrl));
+                Activity act(*logger, lvlTalkative, actUnknown, boostfmt("fetching submodules of '%s'", actualUrl));
                 runProgram("git", true, { "-C", tmpDir, "submodule", "--quiet", "update", "--init", "--recursive" }, true);
             }
 

src/libfetchers/github.cc

@@ -217,7 +217,7 @@ struct GitHubInputScheme : GitArchiveInputScheme
         // is used here. See
         // https://developer.github.com/v3/#authentication and
         // https://docs.github.com/en/developers/apps/authorizing-oath-apps
-        return std::pair<std::string, std::string>("Authorization", fmt("token %s", token));
+        return std::pair<std::string, std::string>("Authorization", boostfmt("token %s", token));
     }
 
     std::string getHost(const Input & input) const
@@ -238,7 +238,7 @@ struct GitHubInputScheme : GitArchiveInputScheme
     Hash getRevFromRef(nix::ref<Store> store, const Input & input) const override
     {
         auto host = getHost(input);
-        auto url = fmt(
+        auto url = boostfmt(
             host == "github.com"
             ? "https://api.%s/repos/%s/%s/commits/%s"
             : "https://%s/api/v3/repos/%s/%s/commits/%s",
@@ -270,7 +270,7 @@ struct GitHubInputScheme : GitArchiveInputScheme
             ? "https://%s/%s/%s/archive/%s.tar.gz"
             : "https://api.%s/repos/%s/%s/tarball/%s";
 
-        const auto url = fmt(urlFmt, host, getOwner(input), getRepo(input),
+        const auto url = boostfmt(urlFmt, host, getOwner(input), getRepo(input),
             input.getRev()->to_string(Base16, false));
 
         return DownloadUrl { url, headers };
@@ -279,7 +279,7 @@ struct GitHubInputScheme : GitArchiveInputScheme
     void clone(const Input & input, const Path & destDir) const override
     {
         auto host = getHost(input);
-        Input::fromURL(fmt("git+https://%s/%s/%s.git",
+        Input::fromURL(boostfmt("git+https://%s/%s/%s.git",
                 host, getOwner(input), getRepo(input)))
             .applyOverrides(input.getRef(), input.getRev())
             .clone(destDir);
@@ -302,7 +302,7 @@ struct GitLabInputScheme : GitArchiveInputScheme
         auto fldsplit = token.find_first_of(':');
         // n.b. C++20 would allow: if (token.starts_with("OAuth2:")) ...
         if ("OAuth2" == token.substr(0, fldsplit))
-            return std::make_pair("Authorization", fmt("Bearer %s", token.substr(fldsplit+1)));
+            return std::make_pair("Authorization", boostfmt("Bearer %s", token.substr(fldsplit+1)));
         if ("PAT" == token.substr(0, fldsplit))
             return std::make_pair("Private-token", token.substr(fldsplit+1));
         warn("Unrecognized GitLab token type %s",  token.substr(0, fldsplit));
@@ -313,7 +313,7 @@ struct GitLabInputScheme : GitArchiveInputScheme
     {
         auto host = maybeGetStrAttr(input.attrs, "host").value_or("gitlab.com");
         // See rate limiting note below
-        auto url = fmt("https://%s/api/v4/projects/%s%%2F%s/repository/commits?ref_name=%s",
+        auto url = boostfmt("https://%s/api/v4/projects/%s%%2F%s/repository/commits?ref_name=%s",
             host, getStrAttr(input.attrs, "owner"), getStrAttr(input.attrs, "repo"), *input.getRef());
 
         Headers headers = makeHeadersWithAuthTokens(host);
@@ -341,7 +341,7 @@ struct GitLabInputScheme : GitArchiveInputScheme
         // is 10 reqs/sec/ip-addr.  See
         // https://docs.gitlab.com/ee/user/gitlab_com/index.html#gitlabcom-specific-rate-limits
         auto host = maybeGetStrAttr(input.attrs, "host").value_or("gitlab.com");
-        auto url = fmt("https://%s/api/v4/projects/%s%%2F%s/repository/archive.tar.gz?sha=%s",
+        auto url = boostfmt("https://%s/api/v4/projects/%s%%2F%s/repository/archive.tar.gz?sha=%s",
             host, getStrAttr(input.attrs, "owner"), getStrAttr(input.attrs, "repo"),
             input.getRev()->to_string(Base16, false));
 
@@ -353,7 +353,7 @@ struct GitLabInputScheme : GitArchiveInputScheme
     {
         auto host = maybeGetStrAttr(input.attrs, "host").value_or("gitlab.com");
         // FIXME: get username somewhere
-        Input::fromURL(fmt("git+https://%s/%s/%s.git",
+        Input::fromURL(boostfmt("git+https://%s/%s/%s.git",
                 host, getStrAttr(input.attrs, "owner"), getStrAttr(input.attrs, "repo")))
             .applyOverrides(input.getRef(), input.getRev())
             .clone(destDir);
@@ -368,7 +368,7 @@ struct SourceHutInputScheme : GitArchiveInputScheme
     {
         // SourceHut supports both PAT and OAuth2. See
         // https://man.sr.ht/meta.sr.ht/oauth.md
-        return std::pair<std::string, std::string>("Authorization", fmt("Bearer %s", token));
+        return std::pair<std::string, std::string>("Authorization", boostfmt("Bearer %s", token));
         // Note: This currently serves no purpose, as this kind of authorization
         // does not allow for downloading tarballs on sourcehut private repos.
         // Once it is implemented, however, should work as expected.
@@ -382,7 +382,7 @@ struct SourceHutInputScheme : GitArchiveInputScheme
         auto ref = *input.getRef();
 
         auto host = maybeGetStrAttr(input.attrs, "host").value_or("git.sr.ht");
-        auto base_url = fmt("https://%s/%s/%s",
+        auto base_url = boostfmt("https://%s/%s/%s",
             host, getStrAttr(input.attrs, "owner"), getStrAttr(input.attrs, "repo"));
 
         Headers headers = makeHeadersWithAuthTokens(host);
@@ -390,7 +390,7 @@ struct SourceHutInputScheme : GitArchiveInputScheme
         std::string refUri;
         if (ref == "HEAD") {
             auto file = store->toRealPath(
-                downloadFile(store, fmt("%s/HEAD", base_url), "source", false, headers).storePath);
+                downloadFile(store, boostfmt("%s/HEAD", base_url), "source", false, headers).storePath);
             std::ifstream is(file);
             std::string line;
             getline(is, line);
@@ -401,12 +401,12 @@ struct SourceHutInputScheme : GitArchiveInputScheme
             }
             refUri = remoteLine->target;
         } else {
-            refUri = fmt("refs/(heads|tags)/%s", ref);
+            refUri = boostfmt("refs/(heads|tags)/%s", ref);
         }
         std::regex refRegex(refUri);
 
         auto file = store->toRealPath(
-            downloadFile(store, fmt("%s/info/refs", base_url), "source", false, headers).storePath);
+            downloadFile(store, boostfmt("%s/info/refs", base_url), "source", false, headers).storePath);
         std::ifstream is(file);
 
         std::string line;
@@ -421,14 +421,14 @@ struct SourceHutInputScheme : GitArchiveInputScheme
             throw BadURL("in '%d', couldn't find ref '%d'", input.to_string(), ref);
 
         auto rev = Hash::parseAny(*id, htSHA1);
-        debug("HEAD revision for '%s' is %s", fmt("%s/%s", base_url, ref), rev.gitRev());
+        debug("HEAD revision for '%s' is %s", boostfmt("%s/%s", base_url, ref), rev.gitRev());
         return rev;
     }
 
     DownloadUrl getDownloadUrl(const Input & input) const override
     {
         auto host = maybeGetStrAttr(input.attrs, "host").value_or("git.sr.ht");
-        auto url = fmt("https://%s/%s/%s/archive/%s.tar.gz",
+        auto url = boostfmt("https://%s/%s/%s/archive/%s.tar.gz",
             host, getStrAttr(input.attrs, "owner"), getStrAttr(input.attrs, "repo"),
             input.getRev()->to_string(Base16, false));
 
@@ -439,7 +439,7 @@ struct SourceHutInputScheme : GitArchiveInputScheme
     void clone(const Input & input, const Path & destDir) const override
     {
         auto host = maybeGetStrAttr(input.attrs, "host").value_or("git.sr.ht");
-        Input::fromURL(fmt("git+https://%s/%s/%s",
+        Input::fromURL(boostfmt("git+https://%s/%s/%s",
                 host, getStrAttr(input.attrs, "owner"), getStrAttr(input.attrs, "repo")))
             .applyOverrides(input.getRef(), input.getRev())
             .clone(destDir);

src/libfetchers/mercurial.cc

@@ -260,7 +260,7 @@ struct MercurialInputScheme : InputScheme
             }
         }
 
-        Path cacheDir = fmt("%s/nix/hg/%s", getCacheDir(), hashString(htSHA256, actualUrl).to_string(Base32, false));
+        Path cacheDir = boostfmt("%s/nix/hg/%s", getCacheDir(), hashString(htSHA256, actualUrl).to_string(Base32, false));
 
         /* If this is a commit hash that we already have, we don't
            have to pull again. */
@@ -268,7 +268,7 @@ struct MercurialInputScheme : InputScheme
                 && pathExists(cacheDir)
                 && runProgram(hgOptions({ "log", "-R", cacheDir, "-r", input.getRev()->gitRev(), "--template", "1" })).second == "1"))
         {
-            Activity act(*logger, lvlTalkative, actUnknown, fmt("fetching Mercurial repository '%s'", actualUrl));
+            Activity act(*logger, lvlTalkative, actUnknown, boostfmt("fetching Mercurial repository '%s'", actualUrl));
 
             if (pathExists(cacheDir)) {
                 try {

src/libfetchers/path.cc

@@ -119,7 +119,7 @@ struct PathInputScheme : InputScheme
         } else
             absPath = path;
 
-        Activity act(*logger, lvlTalkative, actUnknown, fmt("copying '%s'", absPath));
+        Activity act(*logger, lvlTalkative, actUnknown, boostfmt("copying '%s'", absPath));
 
         // FIXME: check whether access to 'path' is allowed.
         auto storePath = store->maybeParseStorePath(absPath);

src/libmain/common-args.cc

@@ -51,7 +51,7 @@ MixCommonArgs::MixCommonArgs(const std::string & programName)
                 globalConfig.getSettings(settings);
                 for (auto & s : settings)
                     if (s.first.starts_with(prefix))
-                        completions.add(s.first, fmt("Set the `%s` setting.", s.first));
+                        completions.add(s.first, boostfmt("Set the `%s` setting.", s.first));
             }
         }
     });

src/libmain/progress-bar.cc

@@ -156,10 +156,10 @@ void ProgressBar::startActivity(
         std::string name(storePathToName(getS(fields, 0)));
         if (name.ends_with(".drv"))
             name = name.substr(0, name.size() - 4);
-        i->s = fmt("building " ANSI_BOLD "%s" ANSI_NORMAL, name);
+        i->s = boostfmt("building " ANSI_BOLD "%s" ANSI_NORMAL, name);
         auto machineName = getS(fields, 1);
         if (machineName != "")
-            i->s += fmt(" on " ANSI_BOLD "%s" ANSI_NORMAL, machineName);
+            i->s += boostfmt(" on " ANSI_BOLD "%s" ANSI_NORMAL, machineName);
 
         // Used to be curRound and nrRounds, but the
         // implementation was broken for a long time.
@@ -172,7 +172,7 @@ void ProgressBar::startActivity(
     if (type == actSubstitute) {
         auto name = storePathToName(getS(fields, 0));
         auto sub = getS(fields, 1);
-        i->s = fmt(
+        i->s = boostfmt(
             sub.starts_with("local")
             ? "copying " ANSI_BOLD "%s" ANSI_NORMAL " from %s"
             : "fetching " ANSI_BOLD "%s" ANSI_NORMAL " from %s",
@@ -183,13 +183,13 @@ void ProgressBar::startActivity(
         auto name = storePathToName(getS(fields, 0));
         if (name.ends_with(".drv"))
             name = name.substr(0, name.size() - 4);
-        i->s = fmt("post-build " ANSI_BOLD "%s" ANSI_NORMAL, name);
+        i->s = boostfmt("post-build " ANSI_BOLD "%s" ANSI_NORMAL, name);
         i->name = DrvName(name).name;
     }
 
     if (type == actQueryPathInfo) {
         auto name = storePathToName(getS(fields, 0));
-        i->s = fmt("querying " ANSI_BOLD "%s" ANSI_NORMAL " on %s", name, getS(fields, 1));
+        i->s = boostfmt("querying " ANSI_BOLD "%s" ANSI_NORMAL " on %s", name, getS(fields, 1));
     }
 
     if ((type == actFileTransfer && hasAncestor(*state, actCopyPath, parent))
@@ -322,7 +322,7 @@ void ProgressBar::eraseProgressDisplay(State & state)
 {
     if (printMultiline && (state.lastLines >= 1)) {
         // FIXME: make sure this works on windows
-        writeToStderr(fmt("\e[G\e[%dF\e[J", state.lastLines));
+        writeToStderr(boostfmt("\e[G\e[%dF\e[J", state.lastLines));
     } else {
         writeToStderr("\r\e[K");
     }
@@ -406,7 +406,7 @@ std::chrono::milliseconds ProgressBar::draw(State & state, const std::optional<s
     }
 
     if (printMultiline && moreActivities)
-        writeToStderr(fmt("And %d more...", moreActivities));
+        writeToStderr(boostfmt("And %d more...", moreActivities));
 
     if (!printMultiline) {
         if (!line.empty()) {
@@ -444,19 +444,19 @@ std::string ProgressBar::getStatus(State & state)
         if (running || done || expected || failed) {
             if (running) {
                 if (expected != 0) {
-                    auto const runningPart = fmt(numberFmt, running / unit);
+                    auto const runningPart = boostfmt(numberFmt, running / unit);
-                    auto const donePart = fmt(numberFmt, done / unit);
+                    auto const donePart = boostfmt(numberFmt, done / unit);
-                    auto const expectedPart = fmt(numberFmt, expected / unit);
+                    auto const expectedPart = boostfmt(numberFmt, expected / unit);
-                    rendered = fmt(
+                    rendered = boostfmt(
                         ANSI_BLUE "%s" ANSI_NORMAL "/" ANSI_GREEN "%s" ANSI_NORMAL "/%s",
                         runningPart,
                         donePart,
                         expectedPart
                     );
                 } else {
-                    auto const runningPart = fmt(numberFmt, running / unit);
+                    auto const runningPart = boostfmt(numberFmt, running / unit);
-                    auto const donePart = fmt(numberFmt, done / unit);
+                    auto const donePart = boostfmt(numberFmt, done / unit);
-                    rendered = fmt(
+                    rendered = boostfmt(
                         ANSI_BLUE "%s" ANSI_NORMAL "/" ANSI_GREEN "%s" ANSI_NORMAL,
                         runningPart,
                         donePart
@@ -464,19 +464,19 @@ std::string ProgressBar::getStatus(State & state)
                 }
             } else if (expected != done) {
                 if (expected != 0) {
-                    auto const donePart = fmt(numberFmt, done / unit);
+                    auto const donePart = boostfmt(numberFmt, done / unit);
-                    auto const expectedPart = fmt(numberFmt, expected / unit);
+                    auto const expectedPart = boostfmt(numberFmt, expected / unit);
-                    rendered = fmt(
+                    rendered = boostfmt(
                         ANSI_GREEN "%s" ANSI_NORMAL "/%s",
                         donePart,
                         expectedPart
                     );
                 } else {
-                    auto const donePart = fmt(numberFmt, done / unit);
+                    auto const donePart = boostfmt(numberFmt, done / unit);
-                    rendered = fmt(ANSI_GREEN "%s" ANSI_NORMAL, donePart);
+                    rendered = boostfmt(ANSI_GREEN "%s" ANSI_NORMAL, donePart);
                 }
             } else {
-                auto const donePart = fmt(numberFmt, done / unit);
+                auto const donePart = boostfmt(numberFmt, done / unit);
 
                 // We only color if `done` is non-zero.
                 if (done) {
@@ -485,10 +485,10 @@ std::string ProgressBar::getStatus(State & state)
                     rendered = donePart;
                 }
             }
-            rendered = fmt(itemFmt, rendered);
+            rendered = boostfmt(itemFmt, rendered);
 
             if (failed)
-                rendered += fmt(" (" ANSI_RED "%d failed" ANSI_NORMAL ")", failed / unit);
+                rendered += boostfmt(" (" ANSI_RED "%d failed" ANSI_NORMAL ")", failed / unit);
         }
 
         return rendered;
@@ -517,7 +517,7 @@ std::string ProgressBar::getStatus(State & state)
     {
         auto s = renderActivity(actOptimiseStore, "%s paths optimised");
         if (s != "") {
-            s += fmt(", %.1f MiB / %d inodes freed", state.bytesLinked / MiB, state.filesLinked);
+            s += boostfmt(", %.1f MiB / %d inodes freed", state.bytesLinked / MiB, state.filesLinked);
             if (!res.empty()) res += ", ";
             res += s;
         }
@@ -528,12 +528,12 @@ std::string ProgressBar::getStatus(State & state)
 
     if (state.corruptedPaths) {
         if (!res.empty()) res += ", ";
-        res += fmt(ANSI_RED "%d corrupted" ANSI_NORMAL, state.corruptedPaths);
+        res += boostfmt(ANSI_RED "%d corrupted" ANSI_NORMAL, state.corruptedPaths);
     }
 
     if (state.untrustedPaths) {
         if (!res.empty()) res += ", ";
-        res += fmt(ANSI_RED "%d untrusted" ANSI_NORMAL, state.untrustedPaths);
+        res += boostfmt(ANSI_RED "%d untrusted" ANSI_NORMAL, state.untrustedPaths);
     }
 
     return res;
@@ -557,7 +557,7 @@ std::optional<char> ProgressBar::ask(std::string_view msg)
 {
     auto state(state_.lock());
     if (state->paused > 0 || !isatty(STDIN_FILENO)) return {};
-    std::cerr << fmt("\r\e[K%s ", msg);
+    std::cerr << boostfmt("\r\e[K%s ", msg);
     auto s = trim(readLine(STDIN_FILENO));
     if (s.size() != 1) return {};
     draw(*state, {});

src/libmain/shared.cc

@@ -280,7 +280,7 @@ void parseCmdLine(const std::string & programName, const Strings & args,
 
 void printVersion(const std::string & programName)
 {
-    std::cout << fmt("%1% (Lix, like Nix) %2%", programName, nixVersion) << std::endl;
+    std::cout << boostfmt("%1% (Lix, like Nix) %2%", programName, nixVersion) << std::endl;
     if (verbosity > lvlNotice) {
         Strings cfg;
 #if HAVE_BOEHMGC
@@ -391,7 +391,7 @@ RunPager::~RunPager()
 PrintFreed::~PrintFreed()
 {
     if (show)
-        std::cout << fmt("%d store paths deleted, %s freed\n",
+        std::cout << boostfmt("%d store paths deleted, %s freed\n",
             results.paths.size(),
             showBytes(results.bytesFreed));
 }

src/libstore/binary-cache-store.cc

@@ -354,7 +354,7 @@ std::shared_ptr<const ValidPathInfo> BinaryCacheStore::queryPathInfoUncached(con
     auto uri = getUri();
     auto storePathS = printStorePath(storePath);
     auto act = std::make_shared<Activity>(*logger, lvlTalkative, actQueryPathInfo,
-        fmt("querying info about '%s' on '%s'", storePathS, uri), Logger::Fields{storePathS, uri});
+        boostfmt("querying info about '%s' on '%s'", storePathS, uri), Logger::Fields{storePathS, uri});
     PushActivity pact(act->id);
 
     auto narInfoFile = narInfoFileFor(storePath);

src/libstore/build/derivation-goal.cc

@@ -71,7 +71,7 @@ DerivationGoal::DerivationGoal(const StorePath & drvPath,
     , buildMode(buildMode)
 {
     state = &DerivationGoal::getDerivation;
-    name = fmt(
+    name = boostfmt(
         "building of '%s' from .drv file",
         DerivedPath::Built { makeConstantStorePathRef(drvPath), wantedOutputs }.to_string(worker.store));
     trace("created");
@@ -92,7 +92,7 @@ DerivationGoal::DerivationGoal(const StorePath & drvPath, const BasicDerivation
     this->drv = std::make_unique<Derivation>(drv);
 
     state = &DerivationGoal::haveDerivation;
-    name = fmt(
+    name = boostfmt(
         "building of '%s' from in-memory derivation",
         DerivedPath::Built { makeConstantStorePathRef(drvPath), drv.outputNames() }.to_string(worker.store));
     trace("created");
@@ -577,7 +577,7 @@ void DerivationGoal::inputsRealised()
 
             auto pathResolved = writeDerivation(worker.store, drvResolved);
 
-            auto msg = fmt("resolved derivation: '%s' -> '%s'",
+            auto msg = boostfmt("resolved derivation: '%s' -> '%s'",
                 worker.store.printStorePath(drvPath),
                 worker.store.printStorePath(pathResolved));
             act = std::make_unique<Activity>(*logger, lvlInfo, actBuildWaiting, msg,
@@ -661,12 +661,12 @@ void DerivationGoal::inputsRealised()
 
 void DerivationGoal::started()
 {
-    auto msg = fmt(
+    auto msg = boostfmt(
         buildMode == bmRepair ? "repairing outputs of '%s'" :
         buildMode == bmCheck ? "checking outputs of '%s'" :
         "building '%s'", worker.store.printStorePath(drvPath));
-    fmt("building '%s'", worker.store.printStorePath(drvPath));
+    boostfmt("building '%s'", worker.store.printStorePath(drvPath));
-    if (hook) msg += fmt(" on '%s'", machineName);
+    if (hook) msg += boostfmt(" on '%s'", machineName);
     act = std::make_unique<Activity>(*logger, lvlInfo, actBuild, msg,
         Logger::Fields{worker.store.printStorePath(drvPath), hook ? machineName : "", 1, 1});
     mcRunningBuilds = std::make_unique<MaintainCount<uint64_t>>(worker.runningBuilds);
@@ -707,7 +707,7 @@ void DerivationGoal::tryToBuild()
     if (!outputLocks.lockPaths(lockFiles, "", false)) {
         if (!actLock)
             actLock = std::make_unique<Activity>(*logger, lvlWarn, actBuildWaiting,
-                fmt("waiting for lock on %s", Magenta(showPaths(lockFiles))));
+                boostfmt("waiting for lock on %s", Magenta(showPaths(lockFiles))));
         worker.waitForAWhile(shared_from_this());
         return;
     }
@@ -761,7 +761,7 @@ void DerivationGoal::tryToBuild()
                    the wake-up timeout expires. */
                 if (!actLock)
                     actLock = std::make_unique<Activity>(*logger, lvlTalkative, actBuildWaiting,
-                        fmt("waiting for a machine to build '%s'", Magenta(worker.store.printStorePath(drvPath))));
+                        boostfmt("waiting for a machine to build '%s'", Magenta(worker.store.printStorePath(drvPath))));
                 worker.waitForAWhile(shared_from_this());
                 outputLocks.unlock();
                 return;
@@ -810,7 +810,7 @@ void replaceValidPath(const Path & storePath, const Path & tmpPath)
        tmpPath (the replacement), so we have to move it out of the
        way first.  We'd better not be interrupted here, because if
        we're repairing (say) Glibc, we end up with a broken system. */
-    Path oldPath = fmt("%1%.old-%2%-%3%", storePath, getpid(), random());
+    Path oldPath = boostfmt("%1%.old-%2%-%3%", storePath, getpid(), random());
     if (pathExists(storePath))
         movePath(storePath, oldPath);
 
@@ -884,7 +884,7 @@ void runPostBuildHook(
         return;
 
     Activity act(logger, lvlTalkative, actPostBuildHook,
-            fmt("running post-build-hook '%s'", settings.postBuildHook),
+            boostfmt("running post-build-hook '%s'", settings.postBuildHook),
             Logger::Fields{store.printStorePath(drvPath)});
     PushActivity pact(act.id);
     std::map<std::string, std::string> hookEnvironment = getEnv();
@@ -978,12 +978,12 @@ void DerivationGoal::buildDone()
 
             diskFull |= cleanupDecideWhetherDiskFull();
 
-            auto msg = fmt("builder for '%s' %s",
+            auto msg = boostfmt("builder for '%s' %s",
                 Magenta(worker.store.printStorePath(drvPath)),
                 statusToString(status));
 
             if (!logger->isVerbose() && !logTail.empty()) {
-                msg += fmt(";\nlast %d log lines:\n", logTail.size());
+                msg += boostfmt(";\nlast %d log lines:\n", logTail.size());
                 for (auto & line : logTail) {
                     msg += "> ";
                     msg += line;
@@ -992,7 +992,7 @@ void DerivationGoal::buildDone()
                 auto nixLogCommand = experimentalFeatureSettings.isEnabled(Xp::NixCommand)
                     ? "nix log"
                     : "nix-store -l";
-                msg += fmt("For full logs, run '" ANSI_BOLD "%s %s" ANSI_NORMAL "'.",
+                msg += boostfmt("For full logs, run '" ANSI_BOLD "%s %s" ANSI_NORMAL "'.",
                     nixLogCommand,
                     worker.store.printStorePath(drvPath));
             }
@@ -1259,10 +1259,10 @@ Path DerivationGoal::openLogFile()
         logDir = localStore->logDir;
     else
         logDir = settings.nixLogDir;
-    Path dir = fmt("%s/%s/%s/", logDir, LocalFSStore::drvsLogDir, baseName.substr(0, 2));
+    Path dir = boostfmt("%s/%s/%s/", logDir, LocalFSStore::drvsLogDir, baseName.substr(0, 2));
     createDirs(dir);
 
-    Path logFileName = fmt("%s/%s%s", dir, baseName.substr(2),
+    Path logFileName = boostfmt("%s/%s%s", dir, baseName.substr(2),
         settings.compressLog ? ".bz2" : "");
 
     fdLogFile = AutoCloseFD{open(logFileName.c_str(), O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC, 0666)};
@@ -1515,7 +1515,7 @@ void DerivationGoal::done(
     outputLocks.unlock();
     buildResult.status = status;
     if (ex)
-        buildResult.errorMsg = fmt("%s", Uncolored(ex->info().msg));
+        buildResult.errorMsg = boostfmt("%s", Uncolored(ex->info().msg));
     if (buildResult.status == BuildResult::TimedOut)
         worker.timedOut = true;
     if (buildResult.status == BuildResult::PermanentFailure)

src/libstore/build/drv-output-substitution-goal.cc

@@ -15,7 +15,7 @@ DrvOutputSubstitutionGoal::DrvOutputSubstitutionGoal(
     , id(id)
 {
     state = &DrvOutputSubstitutionGoal::init;
-    name = fmt("substitution of '%s'", id.to_string());
+    name = boostfmt("substitution of '%s'", id.to_string());
     trace("created");
 }
 

src/libstore/build/goal.cc

@@ -54,7 +54,7 @@ void Goal::waiteeDone(GoalPtr waitee, ExitCode result)
     assert(waitees.count(waitee));
     waitees.erase(waitee);
 
-    trace(fmt("waitee '%s' done; %d left", waitee->name, waitees.size()));
+    trace(boostfmt("waitee '%s' done; %d left", waitee->name, waitees.size()));
 
     if (result == ecFailed || result == ecNoSubstituters || result == ecIncompleteClosure) ++nrFailed;
 

src/libstore/build/local-derivation-goal.cc

@@ -218,7 +218,7 @@ void LocalDerivationGoal::tryLocalBuild()
         if (!buildUser) {
             if (!actLock)
                 actLock = std::make_unique<Activity>(*logger, lvlWarn, actBuildWaiting,
-                    fmt("waiting for a free build user ID for '%s'", Magenta(worker.store.printStorePath(drvPath))));
+                    boostfmt("waiting for a free build user ID for '%s'", Magenta(worker.store.printStorePath(drvPath))));
             worker.waitForAWhile(shared_from_this());
             return;
         }
@@ -452,8 +452,8 @@ void LocalDerivationGoal::startBuilder()
         static std::atomic<unsigned int> counter{0};
 
         cgroup = buildUser
-            ? fmt("%s/nix-build-uid-%d", ourCgroupPath, buildUser->getUID())
+            ? boostfmt("%s/nix-build-uid-%d", ourCgroupPath, buildUser->getUID())
-            : fmt("%s/nix-build-pid-%d-%d", ourCgroupPath, getpid(), counter++);
+            : boostfmt("%s/nix-build-pid-%d-%d", ourCgroupPath, getpid(), counter++);
 
         debug("using cgroup '%s'", *cgroup);
 
@@ -464,7 +464,7 @@ void LocalDerivationGoal::startBuilder()
             auto cgroupsDir = settings.nixStateDir + "/cgroups";
             createDirs(cgroupsDir);
 
-            auto cgroupFile = fmt("%s/%d", cgroupsDir, buildUser->getUID());
+            auto cgroupFile = boostfmt("%s/%d", cgroupsDir, buildUser->getUID());
 
             if (pathExists(cgroupFile)) {
                 auto prevCgroup = readFile(cgroupFile);
@@ -932,7 +932,7 @@ void LocalDerivationGoal::startBuilder()
 
             pid_t child = startProcess([&]() { runChild(); }, options).release();
 
-            writeFull(sendPid.writeSide.get(), fmt("%d\n", child));
+            writeFull(sendPid.writeSide.get(), boostfmt("%d\n", child));
             _exit(0);
         });
 
@@ -962,20 +962,20 @@ void LocalDerivationGoal::startBuilder()
             uid_t nrIds = buildUser ? buildUser->getUIDCount() : 1;
 
             writeFile("/proc/" + std::to_string(pid.get()) + "/uid_map",
-                fmt("%d %d %d", sandboxUid(), hostUid, nrIds));
+                boostfmt("%d %d %d", sandboxUid(), hostUid, nrIds));
 
             if (!buildUser || buildUser->getUIDCount() == 1)
                 writeFile("/proc/" + std::to_string(pid.get()) + "/setgroups", "deny");
 
             writeFile("/proc/" + std::to_string(pid.get()) + "/gid_map",
-                fmt("%d %d %d", sandboxGid(), hostGid, nrIds));
+                boostfmt("%d %d %d", sandboxGid(), hostGid, nrIds));
         } else {
             debug("note: not using a user namespace");
         }
 
         /* Now that we now the sandbox uid, we can write
            /etc/passwd. */
-        writeFile(chrootRootDir + "/etc/passwd", fmt(
+        writeFile(chrootRootDir + "/etc/passwd", boostfmt(
                 "root:x:0:0:Nix build user:%3%:/noshell\n"
                 "nixbld:x:%1%:%2%:Nix build user:%3%:/noshell\n"
                 "nobody:x:65534:65534:Nobody:/:/noshell\n",
@@ -984,25 +984,25 @@ void LocalDerivationGoal::startBuilder()
         /* Declare the build user's group so that programs get a consistent
            view of the system (e.g., "id -gn"). */
         writeFile(chrootRootDir + "/etc/group",
-            fmt("root:x:0:\n"
+            boostfmt("root:x:0:\n"
                 "nixbld:!:%1%:\n"
                 "nogroup:x:65534:\n", sandboxGid()));
 
         /* Save the mount- and user namespace of the child. We have to do this
            *before* the child does a chroot. */
-        sandboxMountNamespace = AutoCloseFD{open(fmt("/proc/%d/ns/mnt", pid.get()).c_str(), O_RDONLY)};
+        sandboxMountNamespace = AutoCloseFD{open(boostfmt("/proc/%d/ns/mnt", pid.get()).c_str(), O_RDONLY)};
         if (sandboxMountNamespace.get() == -1)
             throw SysError("getting sandbox mount namespace");
 
         if (usingUserNamespace) {
-            sandboxUserNamespace = AutoCloseFD{open(fmt("/proc/%d/ns/user", pid.get()).c_str(), O_RDONLY)};
+            sandboxUserNamespace = AutoCloseFD{open(boostfmt("/proc/%d/ns/user", pid.get()).c_str(), O_RDONLY)};
             if (sandboxUserNamespace.get() == -1)
                 throw SysError("getting sandbox user namespace");
         }
 
         /* Move the child into its own cgroup. */
         if (cgroup)
-            writeFile(*cgroup + "/cgroup.procs", fmt("%d", pid.get()));
+            writeFile(*cgroup + "/cgroup.procs", boostfmt("%d", pid.get()));
 
         /* Signal the builder that we've updated its user namespace. */
         writeFull(userNamespaceSync.writeSide.get(), "1");
@@ -1121,7 +1121,7 @@ void LocalDerivationGoal::initEnv()
     env["NIX_STORE"] = worker.store.storeDir;
 
     /* The maximum number of cores to utilize for parallel building. */
-    env["NIX_BUILD_CORES"] = fmt("%d", settings.buildCores);
+    env["NIX_BUILD_CORES"] = boostfmt("%d", settings.buildCores);
 
     initTmpDir();
 
@@ -1877,7 +1877,7 @@ void LocalDerivationGoal::runChild()
             /* Mount a new tmpfs on /dev/shm to ensure that whatever
                the builder puts in /dev/shm is cleaned up automatically. */
             if (pathExists("/dev/shm") && mount("none", (chrootRootDir + "/dev/shm").c_str(), "tmpfs", 0,
-                    fmt("size=%s", settings.sandboxShmSize).c_str()) == -1)
+                    boostfmt("size=%s", settings.sandboxShmSize).c_str()) == -1)
                 throw SysError("mounting /dev/shm");
 
             /* Mount a new devpts on /dev/pts.  Note that this
@@ -2059,7 +2059,7 @@ void LocalDerivationGoal::runChild()
             /* Add the output paths we'll use at build-time to the chroot */
             sandboxProfile += "(allow file-read* file-write* process-exec\n";
             for (auto & [_, path] : scratchOutputs)
-                sandboxProfile += fmt("\t(subpath \"%s\")\n", worker.store.printStorePath(path));
+                sandboxProfile += boostfmt("\t(subpath \"%s\")\n", worker.store.printStorePath(path));
 
             sandboxProfile += ")\n";
 
@@ -2082,16 +2082,16 @@ void LocalDerivationGoal::runChild()
                     throw SysError("getting attributes of path '%s", path);
                 }
                 if (S_ISDIR(st.st_mode))
-                    sandboxProfile += fmt("\t(subpath \"%s\")\n", path);
+                    sandboxProfile += boostfmt("\t(subpath \"%s\")\n", path);
                 else
-                    sandboxProfile += fmt("\t(literal \"%s\")\n", path);
+                    sandboxProfile += boostfmt("\t(literal \"%s\")\n", path);
             }
             sandboxProfile += ")\n";
 
             /* Allow file-read* on full directory hierarchy to self. Allows realpath() */
             sandboxProfile += "(allow file-read*\n";
             for (auto & i : ancestry) {
-                sandboxProfile += fmt("\t(literal \"%s\")\n", i);
+                sandboxProfile += boostfmt("\t(literal \"%s\")\n", i);
             }
             sandboxProfile += ")\n";
 

src/libstore/build/substitution-goal.cc

@@ -13,7 +13,7 @@ PathSubstitutionGoal::PathSubstitutionGoal(const StorePath & storePath, Worker &
     , ca(ca)
 {
     state = &PathSubstitutionGoal::init;
-    name = fmt("substitution of '%s'", worker.store.printStorePath(this->storePath));
+    name = boostfmt("substitution of '%s'", worker.store.printStorePath(this->storePath));
     trace("created");
     maintainExpectedSubstitutions = std::make_unique<MaintainCount<uint64_t>>(worker.expectedSubstitutions);
 }
@@ -82,7 +82,7 @@ void PathSubstitutionGoal::tryNext()
         done(
             substituterFailed ? ecFailed : ecNoSubstituters,
             BuildResult::NoSubstituters,
-            fmt("path '%s' is required, but there is no substituter that can build it", worker.store.printStorePath(storePath)));
+            boostfmt("path '%s' is required, but there is no substituter that can build it", worker.store.printStorePath(storePath)));
 
         if (substituterFailed) {
             worker.failedSubstitutions++;
@@ -184,7 +184,7 @@ void PathSubstitutionGoal::referencesValid()
         done(
             nrNoSubstituters > 0 || nrIncompleteClosure > 0 ? ecIncompleteClosure : ecFailed,
             BuildResult::DependencyFailed,
-            fmt("some references of path '%s' could not be realised", worker.store.printStorePath(storePath)));
+            boostfmt("some references of path '%s' could not be realised", worker.store.printStorePath(storePath)));
         return;
     }
 

src/libstore/filetransfer.cc

@@ -85,7 +85,7 @@ struct curlFileTransfer : public FileTransfer
             : fileTransfer(fileTransfer)
             , request(request)
             , act(*logger, lvlTalkative, actFileTransfer,
-                fmt(request.data ? "uploading '%s'" : "downloading '%s'", request.uri),
+                boostfmt(request.data ? "uploading '%s'" : "downloading '%s'", request.uri),
                 {request.uri}, request.parentAct)
             , callback([cb{std::move(callback)}] (std::exception_ptr ex, FileTransferResult r) {
                 cb(ex);
@@ -99,7 +99,7 @@ struct curlFileTransfer : public FileTransfer
             if (!request.mimeType.empty())
                 requestHeaders = curl_slist_append(requestHeaders, ("Content-Type: " + request.mimeType).c_str());
             for (auto it = request.headers.begin(); it != request.headers.end(); ++it){
-                requestHeaders = curl_slist_append(requestHeaders, fmt("%s: %s", it->first, it->second).c_str());
+                requestHeaders = curl_slist_append(requestHeaders, boostfmt("%s: %s", it->first, it->second).c_str());
             }
         }
 
@@ -415,7 +415,7 @@ struct curlFileTransfer : public FileTransfer
                         std::move(response),
                         "unable to %s '%s': HTTP error %d (%s)%s",
                         request.verb(), request.uri, httpStatus, statusMsg,
-                        code == CURLE_OK ? "" : fmt(" (curl error: %s)", curl_easy_strerror(code)))
+                        code == CURLE_OK ? "" : boostfmt(" (curl error: %s)", curl_easy_strerror(code)))
                     : FileTransferError(err,
                         std::move(response),
                         "unable to %s '%s': %s (%d)",

src/libstore/gc.cc

@@ -32,7 +32,7 @@ static void makeSymlink(const Path & link, const Path & target)
     createDirs(dirOf(link));
 
     /* Create the new symlink. */
-    Path tempLink = fmt("%1%.tmp-%2%-%3%", link, getpid(), random());
+    Path tempLink = boostfmt("%1%.tmp-%2%-%3%", link, getpid(), random());
     createSymlink(target, tempLink);
 
     /* Atomically replace the old one. */
@@ -43,7 +43,7 @@ static void makeSymlink(const Path & link, const Path & target)
 void LocalStore::addIndirectRoot(const Path & path)
 {
     std::string hash = hashString(htSHA1, path).to_string(Base32, false);
-    Path realRoot = canonPath(fmt("%1%/%2%/auto/%3%", stateDir, gcRootsDir, hash));
+    Path realRoot = canonPath(boostfmt("%1%/%2%/auto/%3%", stateDir, gcRootsDir, hash));
     makeSymlink(realRoot, path);
 }
 
@@ -227,7 +227,7 @@ void LocalStore::findTempRoots(Roots & tempRoots, bool censor)
         while ((end = contents.find((char) 0, pos)) != std::string::npos) {
             Path root(contents, pos, end - pos);
             debug("got temporary root '%s'", root);
-            tempRoots[parseStorePath(root)].emplace(censor ? censored : fmt("{temp:%d}", pid));
+            tempRoots[parseStorePath(root)].emplace(censor ? censored : boostfmt("{temp:%d}", pid));
             pos = end + 1;
         }
     }

src/libstore/globals.hh

@@ -897,7 +897,7 @@ public:
         )"};
 
     Setting<std::string> netrcFile{
-        this, fmt("%s/%s", nixConfDir, "netrc"), "netrc-file",
+        this, boostfmt("%s/%s", nixConfDir, "netrc"), "netrc-file",
         R"(
           If set to an absolute path to a `netrc` file, Lix will use the HTTP
           authentication credentials in this file when trying to download from

src/libstore/legacy-ssh-store.cc

@@ -114,7 +114,7 @@ struct LegacySSHStore : public virtual LegacySSHStoreConfig, public virtual Stor
     {
         auto conn = make_ref<Connection>();
         conn->sshConn = master.startCommand(
-            fmt("%s --serve --write", remoteProgram)
+            boostfmt("%s --serve --write", remoteProgram)
             + (remoteStore.get() == "" ? "" : " --store " + shellEscape(remoteStore.get())));
         conn->to = FdSink(conn->sshConn->in.get());
         conn->from = FdSource(conn->sshConn->out.get());

src/libstore/local-binary-cache-store.cc

@@ -60,7 +60,7 @@ protected:
     {
         auto path2 = binaryCacheDir + "/" + path;
         static std::atomic<int> counter{0};
-        Path tmp = fmt("%s.tmp.%d.%d", path2, getpid(), ++counter);
+        Path tmp = boostfmt("%s.tmp.%d.%d", path2, getpid(), ++counter);
         AutoDelete del(tmp, false);
         StreamToSourceAdapter source(istream);
         writeFile(tmp, source);

src/libstore/local-fs-store.cc

@@ -95,8 +95,8 @@ std::optional<std::string> LocalFSStore::getBuildLogExact(const StorePath & path
 
         Path logPath =
             j == 0
-            ? fmt("%s/%s/%s/%s", logDir, drvsLogDir, baseName.substr(0, 2), baseName.substr(2))
+            ? boostfmt("%s/%s/%s/%s", logDir, drvsLogDir, baseName.substr(0, 2), baseName.substr(2))
-            : fmt("%s/%s/%s", logDir, drvsLogDir, baseName);
+            : boostfmt("%s/%s/%s", logDir, drvsLogDir, baseName);
         Path logBz2Path = logPath + ".bz2";
 
         if (pathExists(logPath))

src/libstore/local-store.cc

@@ -168,7 +168,7 @@ void migrateCASchema(SQLite& db, Path schemaPath, AutoCloseFD& lockFd)
             txn.commit();
         }
 
-        writeFile(schemaPath, fmt("%d", nixCASchemaVersion), 0666, true);
+        writeFile(schemaPath, boostfmt("%d", nixCASchemaVersion), 0666, true);
         lockFile(lockFd.get(), ltRead, true);
     }
 }
@@ -184,7 +184,7 @@ LocalStore::LocalStore(const Params & params)
     , reservedPath(dbDir + "/reserved")
     , schemaPath(dbDir + "/schema")
     , tempRootsDir(stateDir + "/temproots")
-    , fnTempRoots(fmt("%s/%d", tempRootsDir, getpid()))
+    , fnTempRoots(boostfmt("%s/%d", tempRootsDir, getpid()))
     , locksHeld(tokenizeString<PathSet>(getEnv("NIX_HELD_LOCKS").value_or("")))
 {
     auto state(_state.lock());
@@ -305,7 +305,7 @@ LocalStore::LocalStore(const Params & params)
     else if (curSchema == 0) { /* new store */
         curSchema = nixSchemaVersion;
         openDB(*state, true);
-        writeFile(schemaPath, fmt("%1%", nixSchemaVersion), 0666, true);
+        writeFile(schemaPath, boostfmt("%1%", nixSchemaVersion), 0666, true);
     }
 
     else if (curSchema < nixSchemaVersion) {
@@ -354,7 +354,7 @@ LocalStore::LocalStore(const Params & params)
             txn.commit();
         }
 
-        writeFile(schemaPath, fmt("%1%", nixSchemaVersion), 0666, true);
+        writeFile(schemaPath, boostfmt("%1%", nixSchemaVersion), 0666, true);
 
         lockFile(globalLock.get(), ltRead, true);
     }
@@ -1915,13 +1915,13 @@ void LocalStore::addBuildLog(const StorePath & drvPath, std::string_view log)
 
     auto baseName = drvPath.to_string();
 
-    auto logPath = fmt("%s/%s/%s/%s.bz2", logDir, drvsLogDir, baseName.substr(0, 2), baseName.substr(2));
+    auto logPath = boostfmt("%s/%s/%s/%s.bz2", logDir, drvsLogDir, baseName.substr(0, 2), baseName.substr(2));
 
     if (pathExists(logPath)) return;
 
     createDirs(dirOf(logPath));
 
-    auto tmpFile = fmt("%s.tmp.%d", logPath, getpid());
+    auto tmpFile = boostfmt("%s.tmp.%d", logPath, getpid());
 
     writeFile(tmpFile, compress("bzip2", log));
 

src/libstore/lock.cc

@@ -76,7 +76,7 @@ struct SimpleUserLock : UserLock
             if (!pw)
                 throw Error("the user '%s' in the group '%s' does not exist", i, settings.buildUsersGroup);
 
-            auto fnUserLock = fmt("%s/userpool/%s", settings.nixStateDir,pw->pw_uid);
+            auto fnUserLock = boostfmt("%s/userpool/%s", settings.nixStateDir,pw->pw_uid);
 
             AutoCloseFD fd{open(fnUserLock.c_str(), O_RDWR | O_CREAT | O_CLOEXEC, 0600)};
             if (!fd)
@@ -148,7 +148,7 @@ struct AutoUserLock : UserLock
 
             createDirs(settings.nixStateDir + "/userpool2");
 
-            auto fnUserLock = fmt("%s/userpool2/slot-%d", settings.nixStateDir, i);
+            auto fnUserLock = boostfmt("%s/userpool2/slot-%d", settings.nixStateDir, i);
 
             AutoCloseFD fd{open(fnUserLock.c_str(), O_RDWR | O_CREAT | O_CLOEXEC, 0600)};
             if (!fd)

src/libstore/optimise-store.cc

@@ -213,7 +213,7 @@ void LocalStore::optimisePath_(Activity * act, OptimiseStats & stats,
        its timestamp back to 0. */
     MakeReadOnly makeReadOnly(mustToggle ? dirOfPath : "");
 
-    Path tempLink = fmt("%1%/.tmp-link-%2%-%3%", realStoreDir, getpid(), random());
+    Path tempLink = boostfmt("%1%/.tmp-link-%2%-%3%", realStoreDir, getpid(), random());
 
     if (link(linkPath.c_str(), tempLink.c_str()) == -1) {
         if (errno == EMLINK) {
@@ -268,7 +268,7 @@ void LocalStore::optimiseStore(OptimiseStats & stats)
         addTempRoot(i);
         if (!isValidPath(i)) continue; /* path was GC'ed, probably */
         {
-            Activity act(*logger, lvlTalkative, actUnknown, fmt("optimising path '%s'", printStorePath(i)));
+            Activity act(*logger, lvlTalkative, actUnknown, boostfmt("optimising path '%s'", printStorePath(i)));
             optimisePath_(&act, stats, realStoreDir + "/" + std::string(i.to_string()), inodeHash, NoRepair);
         }
         done++;

src/libstore/parsed-derivations.cc

@@ -195,7 +195,7 @@ std::string writeStructuredAttrsShell(const nlohmann::json & json)
 
         auto s = handleSimpleType(value);
         if (s)
-            jsonSh += fmt("declare %s=%s\n", key, *s);
+            jsonSh += boostfmt("declare %s=%s\n", key, *s);
 
         else if (value.is_array()) {
             std::string s2;
@@ -208,7 +208,7 @@ std::string writeStructuredAttrsShell(const nlohmann::json & json)
             }
 
             if (good)
-                jsonSh += fmt("declare -a %s=(%s)\n", key, s2);
+                jsonSh += boostfmt("declare -a %s=(%s)\n", key, s2);
         }
 
         else if (value.is_object()) {
@@ -218,11 +218,11 @@ std::string writeStructuredAttrsShell(const nlohmann::json & json)
             for (auto & [key2, value2] : value.items()) {
                 auto s3 = handleSimpleType(value2);
                 if (!s3) { good = false; break; }
-                s2 += fmt("[%s]=%s ", shellEscape(key2), *s3);
+                s2 += boostfmt("[%s]=%s ", shellEscape(key2), *s3);
             }
 
             if (good)
-                jsonSh += fmt("declare -A %s=(%s)\n", key, s2);
+                jsonSh += boostfmt("declare -A %s=(%s)\n", key, s2);
         }
     }
 

src/libstore/platform/darwin.cc

@@ -44,10 +44,10 @@ void DarwinLocalStore::findPlatformRoots(UncheckedRoots & unchecked)
                 throw SysError("Getting pid %1% working directory", pid);
             }
 
-            unchecked[std::string(vnodeInfo.pvi_cdir.vip_path)].emplace(fmt("{libproc/%d/cwd}", pid)
+            unchecked[std::string(vnodeInfo.pvi_cdir.vip_path)].emplace(boostfmt("{libproc/%d/cwd}", pid)
             );
             unchecked[std::string(vnodeInfo.pvi_rdir.vip_path)].emplace(
-                fmt("{libproc/%d/rootdir}", pid)
+                boostfmt("{libproc/%d/rootdir}", pid)
             );
 
             // File descriptors
@@ -87,7 +87,7 @@ void DarwinLocalStore::findPlatformRoots(UncheckedRoots & unchecked)
                 }
 
                 unchecked[std::string(fdInfo.pvip.vip_path)].emplace(
-                    fmt("{libproc/%d/fd/%d}", pid, fd.proc_fd)
+                    boostfmt("{libproc/%d/fd/%d}", pid, fd.proc_fd)
                 );
             }
 
@@ -116,7 +116,7 @@ void DarwinLocalStore::findPlatformRoots(UncheckedRoots & unchecked)
                 }
 
                 unchecked[std::string(regionInfo.prp_vip.vip_path)].emplace(
-                    fmt("{libproc/%d/region}", pid)
+                    boostfmt("{libproc/%d/region}", pid)
                 );
 
                 nextAddr = regionInfo.prp_prinfo.pri_address + regionInfo.prp_prinfo.pri_size;
@@ -167,7 +167,7 @@ void DarwinLocalStore::findPlatformRoots(UncheckedRoots & unchecked)
                      i != env_end;
                      ++i)
                 {
-                    unchecked[i->str()].emplace(fmt("{libproc/%d/environ}", pid));
+                    unchecked[i->str()].emplace(boostfmt("{libproc/%d/environ}", pid));
                 }
             };
 
@@ -203,7 +203,7 @@ void DarwinLocalStore::findPlatformRoots(UncheckedRoots & unchecked)
                     }
 
                     unchecked[std::string(threadPathInfo.pvip.vip_path)].emplace(
-                        fmt("{libproc/%d/thread/%d/cwd}", pid, tid)
+                        boostfmt("{libproc/%d/thread/%d/cwd}", pid, tid)
                     );
                 }
             }

src/libstore/platform/linux.cc

@@ -51,10 +51,10 @@ void LinuxLocalStore::findPlatformRoots(UncheckedRoots & unchecked)
             checkInterrupt();
             if (std::regex_match(ent->d_name, digitsRegex)) {
                 try {
-                    readProcLink(fmt("/proc/%s/exe", ent->d_name), unchecked);
+                    readProcLink(boostfmt("/proc/%s/exe", ent->d_name), unchecked);
-                    readProcLink(fmt("/proc/%s/cwd", ent->d_name), unchecked);
+                    readProcLink(boostfmt("/proc/%s/cwd", ent->d_name), unchecked);
 
-                    auto fdStr = fmt("/proc/%s/fd", ent->d_name);
+                    auto fdStr = boostfmt("/proc/%s/fd", ent->d_name);
                     auto fdDir = AutoCloseDir(opendir(fdStr.c_str()));
                     if (!fdDir) {
                         if (errno == ENOENT || errno == EACCES) {
@@ -65,7 +65,7 @@ void LinuxLocalStore::findPlatformRoots(UncheckedRoots & unchecked)
                     struct dirent * fd_ent;
                     while (errno = 0, fd_ent = readdir(fdDir.get())) {
                         if (fd_ent->d_name[0] != '.') {
-                            readProcLink(fmt("%s/%s", fdStr, fd_ent->d_name), unchecked);
+                            readProcLink(boostfmt("%s/%s", fdStr, fd_ent->d_name), unchecked);
                         }
                     }
                     if (errno) {
@@ -76,7 +76,7 @@ void LinuxLocalStore::findPlatformRoots(UncheckedRoots & unchecked)
                     }
                     fdDir.reset();
 
-                    auto mapFile = fmt("/proc/%s/maps", ent->d_name);
+                    auto mapFile = boostfmt("/proc/%s/maps", ent->d_name);
                     auto mapLines =
                         tokenizeString<std::vector<std::string>>(readFile(mapFile), "\n");
                     for (const auto & line : mapLines) {
@@ -86,7 +86,7 @@ void LinuxLocalStore::findPlatformRoots(UncheckedRoots & unchecked)
                         }
                     }
 
-                    auto envFile = fmt("/proc/%s/environ", ent->d_name);
+                    auto envFile = boostfmt("/proc/%s/environ", ent->d_name);
                     auto envString = readFile(envFile);
                     auto env_end = std::sregex_iterator{};
                     for (auto i =

src/libstore/profiles.cc

@@ -67,7 +67,7 @@ std::pair<Generations, std::optional<GenerationNumber>> findGenerations(Path pro
  */
 static Path makeName(const Path & profile, GenerationNumber num)
 {
-    return fmt("%s-%s-link", profile, num);
+    return boostfmt("%s-%s-link", profile, num);
 }
 
 
@@ -294,7 +294,7 @@ void switchGeneration(
 
 void lockProfile(PathLocks & lock, const Path & profile)
 {
-    lock.lockPaths({profile}, fmt("waiting for lock on profile '%1%'", profile));
+    lock.lockPaths({profile}, boostfmt("waiting for lock on profile '%1%'", profile));
     lock.setDeletion(true);
 }
 

src/libstore/remote-fs-accessor.cc

@@ -19,7 +19,7 @@ RemoteFSAccessor::RemoteFSAccessor(ref<Store> store, const Path & cacheDir)
 Path RemoteFSAccessor::makeCacheFile(std::string_view hashPart, const std::string & ext)
 {
     assert(cacheDir != "");
-    return fmt("%s/%s.%s", cacheDir, hashPart, ext);
+    return boostfmt("%s/%s.%s", cacheDir, hashPart, ext);
 }
 
 ref<FSAccessor> RemoteFSAccessor::addToCache(std::string_view hashPart, std::string && nar)

src/libstore/s3-binary-cache-store.cc

@@ -163,7 +163,7 @@ S3Helper::FileTransferResult S3Helper::getObject(
 
     try {
 
-        auto result = checkAws(fmt("AWS error fetching '%s'", key),
+        auto result = checkAws(boostfmt("AWS error fetching '%s'", key),
             client->GetObject(request));
 
         res.data = decompress(result.GetContentEncoding(),
@@ -417,7 +417,7 @@ struct S3BinaryCacheStoreImpl : virtual S3BinaryCacheStoreConfig, public virtual
 
             request.SetBody(istream);
 
-            auto result = checkAws(fmt("AWS error uploading '%s'", path),
+            auto result = checkAws(boostfmt("AWS error uploading '%s'", path),
                 s3Helper.client->PutObject(request));
         }
 
@@ -482,7 +482,7 @@ struct S3BinaryCacheStoreImpl : virtual S3BinaryCacheStoreConfig, public virtual
         do {
             debug("listing bucket 's3://%s' from key '%s'...", bucketName, marker);
 
-            auto res = checkAws(fmt("AWS error listing bucket '%s'", bucketName),
+            auto res = checkAws(boostfmt("AWS error listing bucket '%s'", bucketName),
                 s3Helper.client->ListObjects(
                     Aws::S3::Model::ListObjectsRequest()
                     .WithBucket(bucketName)

src/libstore/sqlite.cc

@@ -188,14 +188,14 @@ void SQLiteStmt::Use::exec()
     int r = step();
     assert(r != SQLITE_ROW);
     if (r != SQLITE_DONE)
-        SQLiteError::throw_(stmt.db, fmt("executing SQLite statement '%s'", sqlite3_expanded_sql(stmt.stmt)));
+        SQLiteError::throw_(stmt.db, boostfmt("executing SQLite statement '%s'", sqlite3_expanded_sql(stmt.stmt)));
 }
 
 bool SQLiteStmt::Use::next()
 {
     int r = step();
     if (r != SQLITE_DONE && r != SQLITE_ROW)
-        SQLiteError::throw_(stmt.db, fmt("executing SQLite query '%s'", sqlite3_expanded_sql(stmt.stmt)));
+        SQLiteError::throw_(stmt.db, boostfmt("executing SQLite query '%s'", sqlite3_expanded_sql(stmt.stmt)));
     return r == SQLITE_ROW;
 }
 

src/libstore/store-api.cc

@@ -861,13 +861,13 @@ std::string Store::makeValidityRegistration(const StorePathSet & paths,
 
         if (showHash) {
             s += info->narHash.to_string(Base16, false) + "\n";
-            s += fmt("%1%\n", info->narSize);
+            s += boostfmt("%1%\n", info->narSize);
         }
 
         auto deriver = showDerivers && info->deriver ? printStorePath(*info->deriver) : "";
         s += deriver + "\n";
 
-        s += fmt("%1%\n", info->references.size());
+        s += boostfmt("%1%\n", info->references.size());
 
         for (auto & j : info->references)
             s += printStorePath(j) + "\n";
@@ -1019,10 +1019,10 @@ static std::string makeCopyPathMessage(
     std::string_view storePath)
 {
     return srcUri == "local" || srcUri == "daemon"
-        ? fmt("copying path '%s' to '%s'", storePath, dstUri)
+        ? boostfmt("copying path '%s' to '%s'", storePath, dstUri)
         : dstUri == "local" || dstUri == "daemon"
-        ? fmt("copying path '%s' from '%s'", storePath, srcUri)
+        ? boostfmt("copying path '%s' from '%s'", storePath, srcUri)
-        : fmt("copying path '%s' from '%s' to '%s'", storePath, srcUri, dstUri);
+        : boostfmt("copying path '%s' from '%s' to '%s'", storePath, srcUri, dstUri);
 }
 
 
@@ -1146,7 +1146,7 @@ std::map<StorePath, StorePath> copyPaths(
     for (auto & path : storePaths)
         if (!valid.count(path)) missing.insert(path);
 
-    Activity act(*logger, lvlInfo, actCopyPaths, fmt("copying %d paths", missing.size()));
+    Activity act(*logger, lvlInfo, actCopyPaths, boostfmt("copying %d paths", missing.size()));
 
     // In the general case, `addMultipleToStore` requires a sorted list of
     // store paths to add, so sort them right now

src/libutil/cgroup.cc

@@ -93,7 +93,7 @@ static CgroupStats destroyCgroup(const Path & cgroup, bool returnStats)
                 throw Error("invalid pid '%s'", pid);
             if (pidsShown.insert(pid).second) {
                 try {
-                    auto cmdline = readFile(fmt("/proc/%d/cmdline", pid));
+                    auto cmdline = readFile(boostfmt("/proc/%d/cmdline", pid));
                     using namespace std::string_literals;
                     warn("killing stray builder process %d (%s)...",
                         pid, trim(replaceStrings(cmdline, "\0"s, " ")));

src/libutil/config-impl.hh

@@ -83,7 +83,7 @@ void BaseSetting<T>::convertToArg(Args & args, const std::string & category)
 {
     args.addFlag({
         .longName = name,
-        .description = fmt("Set the `%s` setting.", name),
+        .description = boostfmt("Set the `%s` setting.", name),
         .category = category,
         .labels = {"value"},
         .handler = {[this](std::string s) { overridden = true; set(s); }},
@@ -93,7 +93,7 @@ void BaseSetting<T>::convertToArg(Args & args, const std::string & category)
     if (isAppendable())
         args.addFlag({
             .longName = "extra-" + name,
-            .description = fmt("Append to the `%s` setting.", name),
+            .description = boostfmt("Append to the `%s` setting.", name),
             .category = category,
             .labels = {"value"},
             .handler = {[this](std::string s) { overridden = true; set(s, true); }},

src/libutil/config.cc

@@ -185,7 +185,7 @@ std::string Config::toKeyValue()
     std::string res;
     for (const auto & s : _settings)
         if (s.second.isAlias)
-            res += fmt("%s = %s\n", s.first, s.second.setting->to_string());
+            res += boostfmt("%s = %s\n", s.first, s.second.setting->to_string());
     return res;
 }
 
@@ -282,14 +282,14 @@ template<> void BaseSetting<bool>::convertToArg(Args & args, const std::string &
 {
     args.addFlag({
         .longName = name,
-        .description = fmt("Enable the `%s` setting.", name),
+        .description = boostfmt("Enable the `%s` setting.", name),
         .category = category,
         .handler = {[this] { override(true); }},
         .experimentalFeature = experimentalFeature,
     });
     args.addFlag({
         .longName = "no-" + name,
-        .description = fmt("Disable the `%s` setting.", name),
+        .description = boostfmt("Disable the `%s` setting.", name),
         .category = category,
         .handler = {[this] { override(false); }},
         .experimentalFeature = experimentalFeature,
@@ -504,7 +504,7 @@ std::string GlobalConfig::toKeyValue()
     std::map<std::string, Config::SettingInfo> settings;
     globalConfig.getSettings(settings);
     for (const auto & s : settings)
-        res += fmt("%s = %s\n", s.first, s.second.value);
+        res += boostfmt("%s = %s\n", s.first, s.second.value);
     return res;
 }
 

src/libutil/error.cc

@@ -70,7 +70,7 @@ void printCodeLines(std::ostream & out,
     // previous line of code.
     if (loc.prevLineOfCode.has_value()) {
         out << std::endl
-            << fmt("%1% %|2$5d|| %3%",
+            << boostfmt("%1% %|2$5d|| %3%",
             prefix,
             (errPos.line - 1),
             *loc.prevLineOfCode);
@@ -79,7 +79,7 @@ void printCodeLines(std::ostream & out,
     if (loc.errLineOfCode.has_value()) {
         // line of code containing the error.
         out << std::endl
-            << fmt("%1% %|2$5d|| %3%",
+            << boostfmt("%1% %|2$5d|| %3%",
             prefix,
             (errPos.line),
             *loc.errLineOfCode);
@@ -94,7 +94,7 @@ void printCodeLines(std::ostream & out,
             std::string arrows("^");
 
             out << std::endl
-                << fmt("%1%      |%2%" ANSI_RED "%3%" ANSI_NORMAL,
+                << boostfmt("%1%      |%2%" ANSI_RED "%3%" ANSI_NORMAL,
                 prefix,
                 spaces,
                 arrows);
@@ -104,7 +104,7 @@ void printCodeLines(std::ostream & out,
     // next line of code.
     if (loc.nextLineOfCode.has_value()) {
         out << std::endl
-            << fmt("%1% %|2$5d|| %3%",
+            << boostfmt("%1% %|2$5d|| %3%",
             prefix,
             (errPos.line + 1),
             *loc.nextLineOfCode);
@@ -262,7 +262,7 @@ std::ostream & showErrorInfo(std::ostream & out, const ErrorInfo & einfo, bool s
 
     // FIXME: show the program name as part of the trace?
     if (einfo.programName && einfo.programName != ErrorInfo::programName)
-        prefix += fmt(" [%s]:" ANSI_NORMAL " ", einfo.programName.value_or(""));
+        prefix += boostfmt(" [%s]:" ANSI_NORMAL " ", einfo.programName.value_or(""));
     else
         prefix += ":" ANSI_NORMAL " ";
 

src/libutil/file-system.cc

@@ -520,9 +520,9 @@ static Path tempName(Path tmpRoot, const Path & prefix, bool includePid,
 {
     tmpRoot = canonPath(tmpRoot.empty() ? defaultTempDir() : tmpRoot, true);
     if (includePid)
-        return fmt("%1%/%2%-%3%-%4%", tmpRoot, prefix, getpid(), counter++);
+        return boostfmt("%1%/%2%-%3%-%4%", tmpRoot, prefix, getpid(), counter++);
     else
-        return fmt("%1%/%2%-%3%", tmpRoot, prefix, counter++);
+        return boostfmt("%1%/%2%-%3%", tmpRoot, prefix, counter++);
 }
 
 Path createTempDir(const Path & tmpRoot, const Path & prefix,
@@ -577,7 +577,7 @@ void createSymlink(const Path & target, const Path & link)
 void replaceSymlink(const Path & target, const Path & link)
 {
     for (unsigned int n = 0; true; n++) {
-        Path tmp = canonPath(fmt("%s/.%d_%s", dirOf(link), n, baseNameOf(link)));
+        Path tmp = canonPath(boostfmt("%s/.%d_%s", dirOf(link), n, baseNameOf(link)));
 
         try {
             createSymlink(target, tmp);

src/libutil/fmt.hh

@@ -125,18 +125,18 @@ struct HintFmt
  * And `stringFromUserInput` contains formatting placeholders like `%s`, then
  * the code will crash at runtime. `fmt` helps you avoid this pitfall.
  */
-inline std::string fmt(const std::string & s)
+inline std::string boostfmt(const std::string & s)
 {
     return s;
 }
 
-inline std::string fmt(const char * s)
+inline std::string boostfmt(const char * s)
 {
     return s;
 }
 
 template<typename... Args>
-inline std::string fmt(const std::string & fs, const Args &... args)
+inline std::string boostfmt(const std::string & fs, const Args &... args)
 {
     boost::format f(fs);
     fmt_internal::setExceptions(f);

src/libutil/logging.hh

@@ -153,7 +153,7 @@ public:
     template<typename... Args>
     inline void cout(const Args & ... args)
     {
-        writeToStdout(fmt(args...));
+        writeToStdout(boostfmt(args...));
     }
 
     virtual std::optional<char> ask(std::string_view s)
@@ -262,7 +262,7 @@ extern Verbosity verbosity;
     do { \
         auto __lvl = level; \
         if (__lvl <= nix::verbosity) { \
-            loggerParam->log(__lvl, fmt(args)); \
+            loggerParam->log(__lvl, boostfmt(args)); \
         } \
     } while (0)
 #define printMsg(level, args...) printMsgUsing(logger, level, args)

src/libutil/processes.cc

@@ -328,12 +328,12 @@ std::string statusToString(int status)
 {
     if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
         if (WIFEXITED(status))
-            return fmt("failed with exit code %1%", WEXITSTATUS(status));
+            return boostfmt("failed with exit code %1%", WEXITSTATUS(status));
         else if (WIFSIGNALED(status)) {
             int sig = WTERMSIG(status);
 #if HAVE_STRSIGNAL
             const char * description = strsignal(sig);
-            return fmt("failed due to signal %1% (%2%)", sig, description);
+            return boostfmt("failed due to signal %1% (%2%)", sig, description);
 #else
             return fmt("failed due to signal %1%", sig);
 #endif

src/libutil/references.cc

@@ -129,7 +129,7 @@ HashResult HashModuloSink::finish()
        self-references already zeroed out do not produce a hash
        collision. FIXME: proof. */
     for (auto & pos : rewritingSink.matches)
-        hashSink(fmt("|%d", pos));
+        hashSink(boostfmt("|%d", pos));
 
     auto h = hashSink.finish();
     return {h.first, rewritingSink.pos};

src/libutil/strings.cc

@@ -265,7 +265,7 @@ std::pair<std::string_view, std::string_view> getLine(std::string_view s)
 
 std::string showBytes(uint64_t bytes)
 {
-    return fmt("%.2f MiB", bytes / (1024.0 * 1024.0));
+    return boostfmt("%.2f MiB", bytes / (1024.0 * 1024.0));
 }
 
 }

src/libutil/unix-domain-socket.cc

@@ -79,7 +79,7 @@ static void bindConnectProcHelper(
                     throw SysError("cannot %s to socket at '%s'", operationName, path);
                 writeFull(pipe.writeSide.get(), "0\n");
             } catch (SysError & e) {
-                writeFull(pipe.writeSide.get(), fmt("%d\n", e.errNo));
+                writeFull(pipe.writeSide.get(), boostfmt("%d\n", e.errNo));
             } catch (...) {
                 writeFull(pipe.writeSide.get(), "-1\n");
             }

src/libutil/url.cc

@@ -104,7 +104,7 @@ std::string percentEncode(std::string_view s, std::string_view keep)
             || keep.find(c) != std::string::npos)
             res += c;
         else
-            res += fmt("%%%02X", (unsigned int) c);
+            res += boostfmt("%%%02X", (unsigned int) c);
     return res;
 }
 

src/nix-build/nix-build.cc

@@ -170,9 +170,9 @@ static void main_nix_build(int argc, char * * argv)
                 // read the shebang to understand which packages to read from. Since
                 // this is handled via nix-shell -p, we wrap our ruby script execution
                 // in ruby -e 'load' which ignores the shebangs.
-                envCommand = fmt("exec %1% %2% -e 'load(ARGV.shift)' -- %3% %4%", execArgs, interpreter, shellEscape(script), joined.str());
+                envCommand = boostfmt("exec %1% %2% -e 'load(ARGV.shift)' -- %3% %4%", execArgs, interpreter, shellEscape(script), joined.str());
             } else {
-                envCommand = fmt("exec %1% %2% %3% %4%", execArgs, interpreter, shellEscape(script), joined.str());
+                envCommand = boostfmt("exec %1% %2% %3% %4%", execArgs, interpreter, shellEscape(script), joined.str());
             }
         }
 
@@ -488,7 +488,7 @@ static void main_nix_build(int argc, char * * argv)
            environment variables and shell functions.  Also don't
            lose the current $PATH directories. */
         auto rcfile = (Path) tmpDir + "/rc";
-        std::string rc = fmt(
+        std::string rc = boostfmt(
                 R"(_nix_shell_clean_tmpdir() { command rm -rf %1%; }; )"s +
                 (keepTmp ?
                     "trap _nix_shell_clean_tmpdir EXIT; "
@@ -589,7 +589,7 @@ static void main_nix_build(int argc, char * * argv)
             auto & [counter, _wantedOutputs] = drvMap.at({drvPath});
             std::string drvPrefix = outLink;
             if (counter)
-                drvPrefix += fmt("-%d", counter + 1);
+                drvPrefix += boostfmt("-%d", counter + 1);
 
             auto builtOutputs = store->queryPartialDerivationOutputMap(drvPath, &*evalStore);
 

src/nix-env/nix-env.cc

@@ -136,7 +136,7 @@ static void getAllExprs(EvalState & state,
             if (!seen.insert(attrName).second) {
                 std::string suggestionMessage = "";
                 if (path2.path.abs().find("channels") != std::string::npos && path.path.abs().find("channels") != std::string::npos)
-                    suggestionMessage = fmt("\nsuggestion: remove '%s' from either the root channels or the user channels", attrName);
+                    suggestionMessage = boostfmt("\nsuggestion: remove '%s' from either the root channels or the user channels", attrName);
                 printError("warning: name collision in input Nix expressions, skipping '%1%'"
                             "%2%", path2, suggestionMessage);
                 continue;
@@ -357,7 +357,7 @@ static DrvInfos filterBySelector(EvalState & state, const DrvInfos & allElems,
             } else {
                 std::string suggestionMessage = ", maybe you meant:";
                 for (const auto & drvName : prefixHits) {
-                    suggestionMessage += fmt("\n%s", drvName);
+                    suggestionMessage += boostfmt("\n%s", drvName);
                 }
                 throw Error("selector '%1%' matches no derivations" + suggestionMessage, selector.fullName);
             }
@@ -1237,11 +1237,11 @@ static void opQuery(Globals & globals, Strings opFlags, Strings opArgs)
                                 xml.writeEmptyElement("meta", attrs2);
                             } else if (v->type() == nInt) {
                                 attrs2["type"] = "int";
-                                attrs2["value"] = fmt("%1%", v->integer);
+                                attrs2["value"] = boostfmt("%1%", v->integer);
                                 xml.writeEmptyElement("meta", attrs2);
                             } else if (v->type() == nFloat) {
                                 attrs2["type"] = "float";
-                                attrs2["value"] = fmt("%1%", v->fpoint);
+                                attrs2["value"] = boostfmt("%1%", v->fpoint);
                                 xml.writeEmptyElement("meta", attrs2);
                             } else if (v->type() == nBool) {
                                 attrs2["type"] = "bool";

src/nix-instantiate/nix-instantiate.cc

@@ -81,7 +81,7 @@ void processExpr(EvalState & state, const Strings & attrPaths,
                     if (store2)
                         drvPathS = store2->addPermRoot(drvPath, rootName);
                 }
-                std::cout << fmt("%s%s\n", drvPathS, (outputName != "out" ? "!" + outputName : ""));
+                std::cout << boostfmt("%s%s\n", drvPathS, (outputName != "out" ? "!" + outputName : ""));
             }
         }
     }

src/nix-store/dotgraph.cc

@@ -27,7 +27,7 @@ static const std::string & nextColour()
 
 static std::string makeEdge(std::string_view src, std::string_view dst)
 {
-    return fmt("%1% -> %2% [color = %3%];\n",
+    return boostfmt("%1% -> %2% [color = %3%];\n",
         dotQuote(src), dotQuote(dst), dotQuote(nextColour()));
 }
 
@@ -35,7 +35,7 @@ static std::string makeEdge(std::string_view src, std::string_view dst)
 static std::string makeNode(std::string_view id, std::string_view label,
     std::string_view colour)
 {
-    return fmt("%1% [label = %2%, shape = box, "
+    return boostfmt("%1% [label = %2%, shape = box, "
         "style = filled, fillcolor = %3%];\n",
         dotQuote(id), dotQuote(label), dotQuote(colour));
 }

src/nix-store/graphml.cc

@@ -26,14 +26,14 @@ static std::string symbolicName(std::string_view p)
 
 static std::string makeEdge(std::string_view src, std::string_view dst)
 {
-    return fmt("  <edge source=\"%1%\" target=\"%2%\"/>\n",
+    return boostfmt("  <edge source=\"%1%\" target=\"%2%\"/>\n",
         xmlQuote(src), xmlQuote(dst));
 }
 
 
 static std::string makeNode(const ValidPathInfo & info)
 {
-    return fmt(
+    return boostfmt(
         "  <node id=\"%1%\">\n"
         "    <data key=\"narSize\">%2%</data>\n"
         "    <data key=\"name\">%3%</data>\n"

src/nix-store/nix-store.cc

@@ -164,7 +164,7 @@ static void opRealise(Strings opFlags, Strings opArgs)
             auto paths2 = realisePath(i, false);
             if (!noOutput)
                 for (auto & j : paths2)
-                    cout << fmt("%1%\n", j);
+                    cout << boostfmt("%1%\n", j);
         }
 }
 
@@ -175,7 +175,7 @@ static void opAdd(Strings opFlags, Strings opArgs)
     if (!opFlags.empty()) throw UsageError("unknown flag");
 
     for (auto & i : opArgs)
-        cout << fmt("%s\n", store->printStorePath(store->addToStore(std::string(baseNameOf(i)), i)));
+        cout << boostfmt("%s\n", store->printStorePath(store->addToStore(std::string(baseNameOf(i)), i)));
 }
 
 
@@ -196,7 +196,7 @@ static void opAddFixed(Strings opFlags, Strings opArgs)
     opArgs.pop_front();
 
     for (auto & i : opArgs)
-        std::cout << fmt("%s\n", store->printStorePath(store->addToStoreSlow(baseNameOf(i), i, method, hashAlgo).path));
+        std::cout << boostfmt("%s\n", store->printStorePath(store->addToStoreSlow(baseNameOf(i), i, method, hashAlgo).path));
 }
 
 
@@ -217,7 +217,7 @@ static void opPrintFixedPath(Strings opFlags, Strings opArgs)
     std::string hash = *i++;
     std::string name = *i++;
 
-    cout << fmt("%s\n", store->printStorePath(store->makeFixedOutputPath(name, FixedOutputInfo {
+    cout << boostfmt("%s\n", store->printStorePath(store->makeFixedOutputPath(name, FixedOutputInfo {
         .method = method,
         .hash = Hash::parseAny(hash, hashAlgo),
         .references = {},
@@ -251,11 +251,11 @@ static void printTree(const StorePath & path,
     const std::string & firstPad, const std::string & tailPad, StorePathSet & done)
 {
     if (!done.insert(path).second) {
-        cout << fmt("%s%s [...]\n", firstPad, store->printStorePath(path));
+        cout << boostfmt("%s%s [...]\n", firstPad, store->printStorePath(path));
         return;
     }
 
-    cout << fmt("%s%s\n", firstPad, store->printStorePath(path));
+    cout << boostfmt("%s%s\n", firstPad, store->printStorePath(path));
 
     auto info = store->queryPathInfo(path);
 
@@ -330,7 +330,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
             for (auto & i : opArgs) {
                 auto outputs = maybeUseOutputs(store->followLinksToStorePath(i), true, forceRealise);
                 for (auto & outputPath : outputs)
-                    cout << fmt("%1%\n", store->printStorePath(outputPath));
+                    cout << boostfmt("%1%\n", store->printStorePath(outputPath));
             }
             break;
         }
@@ -360,14 +360,14 @@ static void opQuery(Strings opFlags, Strings opArgs)
             auto sorted = store->topoSortPaths(paths);
             for (StorePaths::reverse_iterator i = sorted.rbegin();
                  i != sorted.rend(); ++i)
-                cout << fmt("%s\n", store->printStorePath(*i));
+                cout << boostfmt("%s\n", store->printStorePath(*i));
             break;
         }
 
         case qDeriver:
             for (auto & i : opArgs) {
                 auto info = store->queryPathInfo(store->followLinksToStorePath(i));
-                cout << fmt("%s\n", info->deriver ? store->printStorePath(*info->deriver) : "unknown-deriver");
+                cout << boostfmt("%s\n", info->deriver ? store->printStorePath(*info->deriver) : "unknown-deriver");
             }
             break;
 
@@ -382,7 +382,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
             auto sorted = store->topoSortPaths(result);
             for (StorePaths::reverse_iterator i = sorted.rbegin();
                  i != sorted.rend(); ++i)
-                cout << fmt("%s\n", store->printStorePath(*i));
+                cout << boostfmt("%s\n", store->printStorePath(*i));
             break;
         }
 
@@ -394,7 +394,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
                 if (j == drv.env.end())
                     throw Error("derivation '%s' has no environment binding named '%s'",
                         store->printStorePath(path), bindingName);
-                cout << fmt("%s\n", j->second);
+                cout << boostfmt("%s\n", j->second);
             }
             break;
 
@@ -405,9 +405,9 @@ static void opQuery(Strings opFlags, Strings opArgs)
                     auto info = store->queryPathInfo(j);
                     if (query == qHash) {
                         assert(info->narHash.type == htSHA256);
-                        cout << fmt("%s\n", info->narHash.to_string(Base32, true));
+                        cout << boostfmt("%s\n", info->narHash.to_string(Base32, true));
                     } else if (query == qSize)
-                        cout << fmt("%d\n", info->narSize);
+                        cout << boostfmt("%d\n", info->narSize);
                 }
             }
             break;
@@ -439,7 +439,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
 
         case qResolve: {
             for (auto & i : opArgs)
-                cout << fmt("%s\n", store->printStorePath(store->followLinksToStorePath(i)));
+                cout << boostfmt("%s\n", store->printStorePath(store->followLinksToStorePath(i)));
             break;
         }
 
@@ -458,7 +458,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
             for (auto & [target, links] : roots)
                 if (referrers.find(target) != referrers.end())
                     for (auto & link : links)
-                        cout << fmt("%1% -> %2%\n", link, gcStore.printStorePath(target));
+                        cout << boostfmt("%1% -> %2%\n", link, gcStore.printStorePath(target));
             break;
         }
 
@@ -589,7 +589,7 @@ static void opCheckValidity(Strings opFlags, Strings opArgs)
         auto path = store->followLinksToStorePath(i);
         if (!store->isValidPath(path)) {
             if (printInvalid)
-                cout << fmt("%s\n", store->printStorePath(path));
+                cout << boostfmt("%s\n", store->printStorePath(path));
             else
                 throw Error("path '%s' is not valid", store->printStorePath(path));
         }
@@ -714,7 +714,7 @@ static void opImport(Strings opFlags, Strings opArgs)
     auto paths = store->importPaths(source, NoCheckSigs);
 
     for (auto & i : paths)
-        cout << fmt("%s\n", store->printStorePath(i)) << std::flush;
+        cout << boostfmt("%s\n", store->printStorePath(i)) << std::flush;
 }
 
 

src/nix/build.cc

@@ -49,14 +49,14 @@ static void createOutLinks(const Path& outLink, const std::vector<BuiltPathWithR
         std::visit(overloaded {
             [&](const BuiltPath::Opaque & bo) {
                 std::string symlink = outLink;
-                if (i) symlink += fmt("-%d", i);
+                if (i) symlink += boostfmt("-%d", i);
                 store2.addPermRoot(bo.path, absPath(symlink));
             },
             [&](const BuiltPath::Built & bfd) {
                 for (auto & output : bfd.outputs) {
                     std::string symlink = outLink;
-                    if (i) symlink += fmt("-%d", i);
+                    if (i) symlink += boostfmt("-%d", i);
-                    if (output.first != "out") symlink += fmt("-%s", output.first);
+                    if (output.first != "out") symlink += boostfmt("-%s", output.first);
                     store2.addPermRoot(output.second, absPath(symlink));
                 }
             },

src/nix/bundle.cc

@@ -18,7 +18,7 @@ struct CmdBundle : InstallableCommand
     {
         addFlag({
             .longName = "bundler",
-            .description = fmt("Use a custom bundler instead of the default (`%s`).", bundler),
+            .description = boostfmt("Use a custom bundler instead of the default (`%s`).", bundler),
             .labels = {"flake-url"},
             .handler = {&bundler},
             .completer = {[&](AddCompletions & completions, size_t, std::string_view prefix) {

src/nix/develop.cc

@@ -145,9 +145,9 @@ struct BuildEnvironment
         for (auto & [name, value] : vars) {
             if (!ignoreVars.count(name)) {
                 if (auto str = std::get_if<String>(&value)) {
-                    out << fmt("%s=%s\n", name, shellEscape(str->value));
+                    out << boostfmt("%s=%s\n", name, shellEscape(str->value));
                     if (str->exported)
-                        out << fmt("export %s\n", name);
+                        out << boostfmt("export %s\n", name);
                 }
                 else if (auto arr = std::get_if<Array>(&value)) {
                     out << "declare -a " << name << "=(";
@@ -337,18 +337,18 @@ struct Common : InstallableCommand, MixProfile
         out << "unset shellHook\n";
 
         for (auto & var : savedVars) {
-            out << fmt("%s=${%s:-}\n", var, var);
+            out << boostfmt("%s=${%s:-}\n", var, var);
-            out << fmt("nix_saved_%s=\"$%s\"\n", var, var);
+            out << boostfmt("nix_saved_%s=\"$%s\"\n", var, var);
         }
 
         buildEnvironment.toBash(out, ignoreVars);
 
         for (auto & var : savedVars)
-            out << fmt("%s=\"$%s${nix_saved_%s:+:$nix_saved_%s}\"\n", var, var, var, var);
+            out << boostfmt("%s=\"$%s${nix_saved_%s:+:$nix_saved_%s}\"\n", var, var, var, var);
 
         out << "export NIX_BUILD_TOP=\"$(mktemp -d -t nix-shell.XXXXXX)\"\n";
         for (auto & i : {"TMP", "TMPDIR", "TEMP", "TEMPDIR"})
-            out << fmt("export %s=\"$NIX_BUILD_TOP\"\n", i);
+            out << boostfmt("export %s=\"$NIX_BUILD_TOP\"\n", i);
 
         out << "eval \"${shellHook:-}\"\n";
 
@@ -564,34 +564,34 @@ struct CmdDevelop : Common, MixEnvironment
         if (verbosity >= lvlDebug)
             script += "set -x\n";
 
-        script += fmt("command rm -f '%s'\n", rcFilePath);
+        script += boostfmt("command rm -f '%s'\n", rcFilePath);
 
         if (phase) {
             if (!command.empty())
                 throw UsageError("you cannot use both '--command' and '--phase'");
             // FIXME: foundMakefile is set by buildPhase, need to get
             // rid of that.
-            script += fmt("foundMakefile=1\n");
+            script += boostfmt("foundMakefile=1\n");
-            script += fmt("runHook %1%Phase\n", *phase);
+            script += boostfmt("runHook %1%Phase\n", *phase);
         }
 
         else if (!command.empty()) {
             std::vector<std::string> args;
             for (auto s : command)
                 args.push_back(shellEscape(s));
-            script += fmt("exec %s\n", concatStringsSep(" ", args));
+            script += boostfmt("exec %s\n", concatStringsSep(" ", args));
         }
 
         else {
             script = "[ -n \"$PS1\" ] && [ -e ~/.bashrc ] && source ~/.bashrc;\n" + script;
             if (developSettings.bashPrompt != "")
-                script += fmt("[ -n \"$PS1\" ] && PS1=%s;\n",
+                script += boostfmt("[ -n \"$PS1\" ] && PS1=%s;\n",
                     shellEscape(developSettings.bashPrompt.get()));
             if (developSettings.bashPromptPrefix != "")
-                script += fmt("[ -n \"$PS1\" ] && PS1=%s\"$PS1\";\n",
+                script += boostfmt("[ -n \"$PS1\" ] && PS1=%s\"$PS1\";\n",
                     shellEscape(developSettings.bashPromptPrefix.get()));
             if (developSettings.bashPromptSuffix != "")
-                script += fmt("[ -n \"$PS1\" ] && PS1+=%s;\n",
+                script += boostfmt("[ -n \"$PS1\" ] && PS1+=%s;\n",
                     shellEscape(developSettings.bashPromptSuffix.get()));
         }
 

src/nix/diff-closures.cc

@@ -95,9 +95,9 @@ void printClosureDiff(
         if (showDelta || !removed.empty() || !added.empty()) {
             std::vector<std::string> items;
             if (!removed.empty() || !added.empty())
-                items.push_back(fmt("%s → %s", showVersions(removed), showVersions(added)));
+                items.push_back(boostfmt("%s → %s", showVersions(removed), showVersions(added)));
             if (showDelta)
-                items.push_back(fmt("%s%+.1f KiB" ANSI_NORMAL, sizeDelta > 0 ? ANSI_RED : ANSI_GREEN, sizeDelta / 1024.0));
+                items.push_back(boostfmt("%s%+.1f KiB" ANSI_NORMAL, sizeDelta > 0 ? ANSI_RED : ANSI_GREEN, sizeDelta / 1024.0));
             logger->cout("%s%s: %s", indent, name, concatStringsSep(", ", items));
         }
     }

src/nix/doctor.cc

@@ -17,7 +17,7 @@ std::string formatProtocol(unsigned int proto)
     if (proto) {
         auto major = GET_PROTOCOL_MAJOR(proto) >> 8;
         auto minor = GET_PROTOCOL_MINOR(proto);
-        return fmt("%1%.%2%", major, minor);
+        return boostfmt("%1%.%2%", major, minor);
     }
     return "unknown";
 }
@@ -147,7 +147,7 @@ struct CmdDoctor : StoreCommand
     {
         auto trustedMay = store->isTrustedClient();
         std::string_view trustedness = trustedMay ? (*trustedMay ? "trusted" : "not trusted") : "unknown trust";
-        checkInfo(fmt("You are %s by store uri: %s", trustedness, store->getUri()));
+        checkInfo(boostfmt("You are %s by store uri: %s", trustedness, store->getUri()));
     }
 };
 

src/nix/flake.cc

@@ -396,7 +396,7 @@ struct CmdFlakeCheck : FlakeCommand
         auto checkDerivation = [&](const std::string & attrPath, Value & v, const PosIdx pos) -> std::optional<StorePath> {
             try {
                 Activity act(*logger, lvlInfo, actUnknown,
-                    fmt("checking derivation %s", attrPath));
+                    boostfmt("checking derivation %s", attrPath));
                 auto drvInfo = getDerivation(*state, v, false);
                 if (!drvInfo)
                     throw Error("flake attribute '%s' is not a derivation", attrPath);
@@ -405,7 +405,7 @@ struct CmdFlakeCheck : FlakeCommand
                     auto storePath = drvInfo->queryDrvPath();
                     if (storePath) {
                         logger->log(lvlInfo,
-                            fmt("derivation evaluated to %s",
+                            boostfmt("derivation evaluated to %s",
                                 store->printStorePath(storePath.value())));
                     }
                     return storePath;
@@ -438,7 +438,7 @@ struct CmdFlakeCheck : FlakeCommand
         auto checkOverlay = [&](const std::string & attrPath, Value & v, const PosIdx pos) {
             try {
                 Activity act(*logger, lvlInfo, actUnknown,
-                    fmt("checking overlay '%s'", attrPath));
+                    boostfmt("checking overlay '%s'", attrPath));
                 state->forceValue(v, pos);
                 if (!v.isLambda()) {
                     throw Error("overlay is not a function, but %s instead", showType(v));
@@ -462,7 +462,7 @@ struct CmdFlakeCheck : FlakeCommand
         auto checkModule = [&](const std::string & attrPath, Value & v, const PosIdx pos) {
             try {
                 Activity act(*logger, lvlInfo, actUnknown,
-                    fmt("checking NixOS module '%s'", attrPath));
+                    boostfmt("checking NixOS module '%s'", attrPath));
                 state->forceValue(v, pos);
             } catch (Error & e) {
                 e.addTrace(resolve(pos), HintFmt("while checking the NixOS module '%s'", attrPath));
@@ -475,7 +475,7 @@ struct CmdFlakeCheck : FlakeCommand
         checkHydraJobs = [&](const std::string & attrPath, Value & v, const PosIdx pos) {
             try {
                 Activity act(*logger, lvlInfo, actUnknown,
-                    fmt("checking Hydra job '%s'", attrPath));
+                    boostfmt("checking Hydra job '%s'", attrPath));
                 state->forceAttrs(v, pos, "");
 
                 if (state->isDerivation(v))
@@ -486,7 +486,7 @@ struct CmdFlakeCheck : FlakeCommand
                     auto attrPath2 = concatStrings(attrPath, ".", state->symbols[attr.name]);
                     if (state->isDerivation(*attr.value)) {
                         Activity act(*logger, lvlInfo, actUnknown,
-                            fmt("checking Hydra job '%s'", attrPath2));
+                            boostfmt("checking Hydra job '%s'", attrPath2));
                         checkDerivation(attrPath2, *attr.value, attr.pos);
                     } else
                         checkHydraJobs(attrPath2, *attr.value, attr.pos);
@@ -501,7 +501,7 @@ struct CmdFlakeCheck : FlakeCommand
         auto checkNixOSConfiguration = [&](const std::string & attrPath, Value & v, const PosIdx pos) {
             try {
                 Activity act(*logger, lvlInfo, actUnknown,
-                    fmt("checking NixOS configuration '%s'", attrPath));
+                    boostfmt("checking NixOS configuration '%s'", attrPath));
                 Bindings & bindings(*state->allocBindings(0));
                 auto vToplevel = findAlongAttrPath(*state, "config.system.build.toplevel", bindings, v).first;
                 state->forceValue(*vToplevel, pos);
@@ -516,7 +516,7 @@ struct CmdFlakeCheck : FlakeCommand
         auto checkTemplate = [&](const std::string & attrPath, Value & v, const PosIdx pos) {
             try {
                 Activity act(*logger, lvlInfo, actUnknown,
-                    fmt("checking template '%s'", attrPath));
+                    boostfmt("checking template '%s'", attrPath));
 
                 state->forceAttrs(v, pos, "");
 
@@ -550,7 +550,7 @@ struct CmdFlakeCheck : FlakeCommand
         auto checkBundler = [&](const std::string & attrPath, Value & v, const PosIdx pos) {
             try {
                 Activity act(*logger, lvlInfo, actUnknown,
-                    fmt("checking bundler '%s'", attrPath));
+                    boostfmt("checking bundler '%s'", attrPath));
                 state->forceValue(v, pos);
                 if (!v.isLambda())
                     throw Error("bundler must be a function");
@@ -571,7 +571,7 @@ struct CmdFlakeCheck : FlakeCommand
                 *vFlake,
                 [&](const std::string & name, Value & vOutput, const PosIdx pos) {
                     Activity act(*logger, lvlInfo, actUnknown,
-                        fmt("checking flake output '%s'", name));
+                        boostfmt("checking flake output '%s'", name));
 
                     try {
                         evalSettings.enableImportFromDerivation.setDefault(name != "hydraJobs");
@@ -599,7 +599,7 @@ struct CmdFlakeCheck : FlakeCommand
                                     state->forceAttrs(*attr.value, attr.pos, "");
                                     for (auto & attr2 : *attr.value->attrs) {
                                         auto drvPath = checkDerivation(
-                                            fmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]),
+                                            boostfmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]),
                                             *attr2.value, attr2.pos);
                                         if (drvPath && attr_name == settings.thisSystem.get()) {
                                             drvPaths.push_back(DerivedPath::Built {
@@ -619,7 +619,7 @@ struct CmdFlakeCheck : FlakeCommand
                                 checkSystemName(attr_name, attr.pos);
                                 if (checkSystemType(attr_name, attr.pos)) {
                                     checkApp(
-                                        fmt("%s.%s", name, attr_name),
+                                        boostfmt("%s.%s", name, attr_name),
                                         *attr.value, attr.pos);
                                 };
                             }
@@ -634,7 +634,7 @@ struct CmdFlakeCheck : FlakeCommand
                                     state->forceAttrs(*attr.value, attr.pos, "");
                                     for (auto & attr2 : *attr.value->attrs)
                                         checkDerivation(
-                                            fmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]),
+                                            boostfmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]),
                                             *attr2.value, attr2.pos);
                                 };
                             }
@@ -649,7 +649,7 @@ struct CmdFlakeCheck : FlakeCommand
                                     state->forceAttrs(*attr.value, attr.pos, "");
                                     for (auto & attr2 : *attr.value->attrs)
                                         checkApp(
-                                            fmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]),
+                                            boostfmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]),
                                             *attr2.value, attr2.pos);
                                 };
                             }
@@ -662,7 +662,7 @@ struct CmdFlakeCheck : FlakeCommand
                                 checkSystemName(attr_name, attr.pos);
                                 if (checkSystemType(attr_name, attr.pos)) {
                                     checkDerivation(
-                                        fmt("%s.%s", name, attr_name),
+                                        boostfmt("%s.%s", name, attr_name),
                                         *attr.value, attr.pos);
                                 };
                             }
@@ -675,7 +675,7 @@ struct CmdFlakeCheck : FlakeCommand
                                 checkSystemName(attr_name, attr.pos);
                                 if (checkSystemType(attr_name, attr.pos) ) {
                                     checkApp(
-                                        fmt("%s.%s", name, attr_name),
+                                        boostfmt("%s.%s", name, attr_name),
                                         *attr.value, attr.pos);
                                 };
                             }
@@ -696,7 +696,7 @@ struct CmdFlakeCheck : FlakeCommand
                         else if (name == "overlays") {
                             state->forceAttrs(vOutput, pos, "");
                             for (auto & attr : *vOutput.attrs)
-                                checkOverlay(fmt("%s.%s", name, state->symbols[attr.name]),
+                                checkOverlay(boostfmt("%s.%s", name, state->symbols[attr.name]),
                                     *attr.value, attr.pos);
                         }
 
@@ -706,14 +706,14 @@ struct CmdFlakeCheck : FlakeCommand
                         else if (name == "nixosModules") {
                             state->forceAttrs(vOutput, pos, "");
                             for (auto & attr : *vOutput.attrs)
-                                checkModule(fmt("%s.%s", name, state->symbols[attr.name]),
+                                checkModule(boostfmt("%s.%s", name, state->symbols[attr.name]),
                                     *attr.value, attr.pos);
                         }
 
                         else if (name == "nixosConfigurations") {
                             state->forceAttrs(vOutput, pos, "");
                             for (auto & attr : *vOutput.attrs)
-                                checkNixOSConfiguration(fmt("%s.%s", name, state->symbols[attr.name]),
+                                checkNixOSConfiguration(boostfmt("%s.%s", name, state->symbols[attr.name]),
                                     *attr.value, attr.pos);
                         }
 
@@ -726,7 +726,7 @@ struct CmdFlakeCheck : FlakeCommand
                         else if (name == "templates") {
                             state->forceAttrs(vOutput, pos, "");
                             for (auto & attr : *vOutput.attrs)
-                                checkTemplate(fmt("%s.%s", name, state->symbols[attr.name]),
+                                checkTemplate(boostfmt("%s.%s", name, state->symbols[attr.name]),
                                     *attr.value, attr.pos);
                         }
 
@@ -737,7 +737,7 @@ struct CmdFlakeCheck : FlakeCommand
                                 checkSystemName(attr_name, attr.pos);
                                 if (checkSystemType(attr_name, attr.pos)) {
                                     checkBundler(
-                                        fmt("%s.%s", name, attr_name),
+                                        boostfmt("%s.%s", name, attr_name),
                                         *attr.value, attr.pos);
                                 };
                             }
@@ -752,7 +752,7 @@ struct CmdFlakeCheck : FlakeCommand
                                     state->forceAttrs(*attr.value, attr.pos, "");
                                     for (auto & attr2 : *attr.value->attrs) {
                                         checkBundler(
-                                            fmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]),
+                                            boostfmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]),
                                             *attr2.value, attr2.pos);
                                     }
                                 };
@@ -784,7 +784,7 @@ struct CmdFlakeCheck : FlakeCommand
 
         if (build && !drvPaths.empty()) {
             Activity act(*logger, lvlInfo, actUnknown,
-                fmt("running %d flake checks", drvPaths.size()));
+                boostfmt("running %d flake checks", drvPaths.size()));
             store->buildPaths(drvPaths);
         }
         if (hasErrors)
@@ -1196,7 +1196,7 @@ struct CmdFlakeShow : FlakeCommand, MixJSON
             auto attrPathS = state->symbols.resolve(attrPath);
 
             Activity act(*logger, lvlInfo, actUnknown,
-                fmt("evaluating '%s'", concatStringsSep(".", attrPathS)));
+                boostfmt("evaluating '%s'", concatStringsSep(".", attrPathS)));
 
             try {
                 auto recurse = [&]()
@@ -1216,7 +1216,7 @@ struct CmdFlakeShow : FlakeCommand, MixJSON
                         auto attrPath2(attrPath);
                         attrPath2.push_back(attr);
                         auto j2 = visit(*visitor2, attrPath2,
-                            fmt(ANSI_GREEN "%s%s" ANSI_NORMAL ANSI_BOLD "%s" ANSI_NORMAL, nextPrefix, last ? treeLast : treeConn, attrName),
+                            boostfmt(ANSI_GREEN "%s%s" ANSI_NORMAL ANSI_BOLD "%s" ANSI_NORMAL, nextPrefix, last ? treeLast : treeConn, attrName),
                             nextPrefix + (last ? treeNull : treeLine));
                         if (json) j.emplace(attrName, std::move(j2));
                     }
@@ -1274,9 +1274,9 @@ struct CmdFlakeShow : FlakeCommand, MixJSON
                 {
                     if (!showAllSystems && std::string(attrPathS[1]) != localSystem) {
                         if (!json)
-                            logger->cout(fmt("%s " ANSI_WARNING "omitted" ANSI_NORMAL " (use '--all-systems' to show)", headerPrefix));
+                            logger->cout(boostfmt("%s " ANSI_WARNING "omitted" ANSI_NORMAL " (use '--all-systems' to show)", headerPrefix));
                         else {
-                            logger->warn(fmt("%s omitted (use '--all-systems' to show)", concatStringsSep(".", attrPathS)));
+                            logger->warn(boostfmt("%s omitted (use '--all-systems' to show)", concatStringsSep(".", attrPathS)));
                         }
                     } else {
                         if (visitor.isDerivation())
@@ -1298,15 +1298,15 @@ struct CmdFlakeShow : FlakeCommand, MixJSON
                         recurse();
                     else if (!showLegacy){
                         if (!json)
-                            logger->cout(fmt("%s " ANSI_WARNING "omitted" ANSI_NORMAL " (use '--legacy' to show)", headerPrefix));
+                            logger->cout(boostfmt("%s " ANSI_WARNING "omitted" ANSI_NORMAL " (use '--legacy' to show)", headerPrefix));
                         else {
-                            logger->warn(fmt("%s omitted (use '--legacy' to show)", concatStringsSep(".", attrPathS)));
+                            logger->warn(boostfmt("%s omitted (use '--legacy' to show)", concatStringsSep(".", attrPathS)));
                         }
                     } else if (!showAllSystems && std::string(attrPathS[1]) != localSystem) {
                         if (!json)
-                            logger->cout(fmt("%s " ANSI_WARNING "omitted" ANSI_NORMAL " (use '--all-systems' to show)", headerPrefix));
+                            logger->cout(boostfmt("%s " ANSI_WARNING "omitted" ANSI_NORMAL " (use '--all-systems' to show)", headerPrefix));
                         else {
-                            logger->warn(fmt("%s omitted (use '--all-systems' to show)", concatStringsSep(".", attrPathS)));
+                            logger->warn(boostfmt("%s omitted (use '--all-systems' to show)", concatStringsSep(".", attrPathS)));
                         }
                     } else {
                         if (visitor.isDerivation())
@@ -1368,7 +1368,7 @@ struct CmdFlakeShow : FlakeCommand, MixJSON
 
         auto cache = openEvalCache(*state, flake);
 
-        auto j = visit(*cache->getRoot(), {}, fmt(ANSI_BOLD "%s" ANSI_NORMAL, flake->flake.lockedRef), "");
+        auto j = visit(*cache->getRoot(), {}, boostfmt(ANSI_BOLD "%s" ANSI_NORMAL, flake->flake.lockedRef), "");
         if (json)
             logger->cout("%s", j.dump());
     }

src/nix/hash.cc

@@ -113,7 +113,7 @@ struct CmdToBase : Command
 
     std::string description() override
     {
-        return fmt("convert a hash to %s representation",
+        return boostfmt("convert a hash to %s representation",
             base == Base16 ? "base-16" :
             base == Base32 ? "base-32" :
             base == Base64 ? "base-64" :

src/nix/ls.cc

@@ -51,7 +51,7 @@ struct MixLs : virtual Args, MixJSON
                         (st.isExecutable ? "-r-xr-xr-x" : "-r--r--r--") :
                     st.type == FSAccessor::Type::tSymlink ? "lrwxrwxrwx" :
                     "dr-xr-xr-x";
-                auto line = fmt("%s %20d %s", tp, st.fileSize, relPath);
+                auto line = boostfmt("%s %20d %s", tp, st.fileSize, relPath);
                 if (st.type == FSAccessor::Type::tSymlink)
                     line += " -> " + accessor->readLink(curPath);
                 logger->cout(line);

src/nix/main.cc

@@ -220,7 +220,7 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs, virtual RootArgs
    lowdown. */
 static void showHelp(std::vector<std::string> subcommand, NixArgs & toplevel)
 {
-    auto mdName = subcommand.empty() ? "nix" : fmt("nix3-%s", concatStringsSep("-", subcommand));
+    auto mdName = subcommand.empty() ? "nix" : boostfmt("nix3-%s", concatStringsSep("-", subcommand));
 
     evalSettings.restrictEval = false;
     evalSettings.pureEval = false;

src/nix/path-info.cc

@@ -64,7 +64,7 @@ struct CmdPathInfo : StorePathsCommand, MixJSON
     void printSize(uint64_t value)
     {
         if (!humanReadable) {
-            std::cout << fmt("\t%11d", value);
+            std::cout << boostfmt("\t%11d", value);
             return;
         }
 
@@ -77,7 +77,7 @@ struct CmdPathInfo : StorePathsCommand, MixJSON
             ++power;
             res /= 1024;
         }
-        std::cout << fmt("\t%6.1f%c", res, idents.at(power));
+        std::cout << boostfmt("\t%6.1f%c", res, idents.at(power));
     }
 
     void run(ref<Store> store, StorePaths && storePaths) override

src/nix/prefetch.cc

@@ -104,7 +104,7 @@ std::tuple<StorePath, Hash> prefetchFile(
         /* Optionally unpack the file. */
         if (unpack) {
             Activity act(*logger, lvlChatty, actUnknown,
-                fmt("unpacking '%s'", url));
+                boostfmt("unpacking '%s'", url));
             Path unpacked = (Path) tmpDir + "/unpacked";
             createDirs(unpacked);
             unpackTarfile(tmpFile, unpacked);
@@ -119,7 +119,7 @@ std::tuple<StorePath, Hash> prefetchFile(
         }
 
         Activity act(*logger, lvlChatty, actUnknown,
-            fmt("adding '%s' to the store", url));
+            boostfmt("adding '%s' to the store", url));
 
         auto info = store->addToStoreSlow(*name, tmpFile, ingestionMethod, hashType, expectedHash);
         storePath = info.path;

src/nix/profile.cc

@@ -328,7 +328,7 @@ struct CmdProfileUpgrade : virtual SourceExprCommand, MixDefaultProfile, MixProf
                 *logger,
                 lvlChatty,
                 actUnknown,
-                fmt("checking '%s' for updates", element.source->attrPath),
+                boostfmt("checking '%s' for updates", element.source->attrPath),
                 Logger::Fields{element.source->attrPath}
             );
 
@@ -518,7 +518,7 @@ struct CmdProfileHistory : virtual StoreCommand, EvalCommand, MixDefaultProfile
                 gen.number == curGen ? ANSI_GREEN : ANSI_BOLD,
                 gen.number,
                 std::put_time(std::gmtime(&gen.creationTime), "%Y-%m-%d"),
-                prevGen ? fmt(" <- %d", prevGen->first.number) : "");
+                prevGen ? boostfmt(" <- %d", prevGen->first.number) : "");
 
             ProfileManifest::printDiff(
                 prevGen ? prevGen->second : ProfileManifest(),

src/nix/run.cc

@@ -275,8 +275,8 @@ void chrootHelper(int argc, char * * argv)
             throw SysError("mounting '%s' on '%s'", realStoreDir, storeDir);
 
     writeFile("/proc/self/setgroups", "deny");
-    writeFile("/proc/self/uid_map", fmt("%d %d %d", uid, uid, 1));
+    writeFile("/proc/self/uid_map", boostfmt("%d %d %d", uid, uid, 1));
-    writeFile("/proc/self/gid_map", fmt("%d %d %d", gid, gid, 1));
+    writeFile("/proc/self/gid_map", boostfmt("%d %d %d", gid, gid, 1));
 
     if (system != "")
         setPersonality(system);

src/nix/search.cc

@@ -98,7 +98,7 @@ struct CmdSearch : InstallableCommand, MixJSON
             auto attrPathS = state->symbols.resolve(attrPath);
 
             Activity act(*logger, lvlInfo, actUnknown,
-                fmt("evaluating '%s'", concatStringsSep(".", attrPathS)));
+                boostfmt("evaluating '%s'", concatStringsSep(".", attrPathS)));
             try {
                 auto recurse = [&]()
                 {

src/nix/upgrade-nix.cc

@@ -93,12 +93,12 @@ struct CmdUpgradeNix : MixDryRun, EvalCommand
         }
 
         {
-            Activity act(*logger, lvlInfo, actUnknown, fmt("downloading '%s'...", store->printStorePath(storePath)));
+            Activity act(*logger, lvlInfo, actUnknown, boostfmt("downloading '%s'...", store->printStorePath(storePath)));
             store->ensurePath(storePath);
         }
 
         {
-            Activity act(*logger, lvlInfo, actUnknown, fmt("verifying that '%s' works...", store->printStorePath(storePath)));
+            Activity act(*logger, lvlInfo, actUnknown, boostfmt("verifying that '%s' works...", store->printStorePath(storePath)));
             auto program = store->printStorePath(storePath) + "/bin/nix-env";
             auto s = runProgram(program, false, {"--version"});
             if (s.find("Nix") == std::string::npos)

src/nix/verify.cc

@@ -94,7 +94,7 @@ struct CmdVerify : StorePathsCommand
                 // Note: info->path can be different from storePath
                 // for binary cache stores when using --all (since we
                 // can't enumerate names efficiently).
-                Activity act2(*logger, lvlInfo, actUnknown, fmt("checking '%s'", store->printStorePath(info->path)));
+                Activity act2(*logger, lvlInfo, actUnknown, boostfmt("checking '%s'", store->printStorePath(info->path)));
 
                 if (!noContents) {
 

src/nix/why-depends.cc

@@ -234,7 +234,7 @@ struct CmdWhyDepends : SourceExprCommand, MixOperateOnOptions
                         if (pos != std::string::npos) {
                             size_t margin = 32;
                             auto pos2 = pos >= margin ? pos - margin : 0;
-                            hits[hash].emplace_back(fmt("%s: …%s…",
+                            hits[hash].emplace_back(boostfmt("%s: …%s…",
                                     p2,
                                     hilite(filterPrintable(
                                             std::string(contents, pos2, pos - pos2 + hash.size() + margin)),
@@ -250,7 +250,7 @@ struct CmdWhyDepends : SourceExprCommand, MixOperateOnOptions
                     for (auto & hash : hashes) {
                         auto pos = target.find(hash);
                         if (pos != std::string::npos)
-                            hits[hash].emplace_back(fmt("%s -> %s", p2,
+                            hits[hash].emplace_back(boostfmt("%s -> %s", p2,
                                     hilite(target, pos, StorePath::HashLen, getColour(hash))));
                     }
                 }

src/resolve-system-dependencies/resolve-system-dependencies.cc

@@ -157,9 +157,9 @@ int main(int argc, char ** argv)
 
         uname(&_uname);
 
-        auto cacheParentDir = fmt("%1%/dependency-maps", settings.nixStateDir);
+        auto cacheParentDir = boostfmt("%1%/dependency-maps", settings.nixStateDir);
 
-        cacheDir = fmt("%1%/%2%-%3%-%4%", cacheParentDir, _uname.machine, _uname.sysname, _uname.release);
+        cacheDir = boostfmt("%1%/%2%-%3%-%4%", cacheParentDir, _uname.machine, _uname.sysname, _uname.release);
 
         mkdir(cacheParentDir.c_str(), 0755);
         mkdir(cacheDir.c_str(), 0755);

tests/unit/libcmd/args.cc

@@ -25,7 +25,7 @@ TEST(Arguments, lookupFileArg) {
     // Meson should be allowed to pass us a relative path here tbh.
     auto const canonDataPath = CanonPath::fromCwd(unitDataPath);
 
-    std::string const searchPathElem = fmt("example=%s", unitDataPath);
+    std::string const searchPathElem = boostfmt("example=%s", unitDataPath);
 
     SearchPath searchPath;
     searchPath.elements.push_back(SearchPath::Elem::parse(searchPathElem));

tests/unit/libexpr-support/tests/libexpr.hh

@@ -66,21 +66,21 @@ namespace nix {
         return arg.type() == nAttrs;
     }
 
-    MATCHER_P(IsStringEq, s, fmt("The string is equal to \"%1%\"", s)) {
+    MATCHER_P(IsStringEq, s, boostfmt("The string is equal to \"%1%\"", s)) {
         if (arg.type() != nString) {
             return false;
         }
         return std::string_view(arg.string.s) == std::string_view(s);
     }
 
-    MATCHER_P(IsIntEq, v, fmt("The string is equal to \"%1%\"", v)) {
+    MATCHER_P(IsIntEq, v, boostfmt("The string is equal to \"%1%\"", v)) {
         if (arg.type() != nInt) {
             return false;
         }
         return arg.integer == v;
     }
 
-    MATCHER_P(IsFloatEq, v, fmt("The float is equal to \"%1%\"", v)) {
+    MATCHER_P(IsFloatEq, v, boostfmt("The float is equal to \"%1%\"", v)) {
         if (arg.type() != nFloat) {
             return false;
         }
@@ -101,7 +101,7 @@ namespace nix {
         return arg.boolean == false;
     }
 
-    MATCHER_P(IsPathEq, p, fmt("Is a path equal to \"%1%\"", p)) {
+    MATCHER_P(IsPathEq, p, boostfmt("Is a path equal to \"%1%\"", p)) {
             if (arg.type() != nPath) {
                 *result_listener << "Expected a path got " << arg.type();
                 return false;
@@ -113,7 +113,7 @@ namespace nix {
     }
 
 
-    MATCHER_P(IsListOfSize, n, fmt("Is a list of size [%1%]", n)) {
+    MATCHER_P(IsListOfSize, n, boostfmt("Is a list of size [%1%]", n)) {
         if (arg.type() != nList) {
             *result_listener << "Expected list got " << arg.type();
             return false;
@@ -124,7 +124,7 @@ namespace nix {
         return true;
     }
 
-    MATCHER_P(IsAttrsOfSize, n, fmt("Is a set of size [%1%]", n)) {
+    MATCHER_P(IsAttrsOfSize, n, boostfmt("Is a set of size [%1%]", n)) {
         if (arg.type() != nAttrs) {
             *result_listener << "Expected set got " << arg.type();
             return false;

tests/unit/libexpr/primops.cc

@@ -687,7 +687,7 @@ namespace nix {
 
     TEST_P(ParseDrvNamePrimOpTest, parseDrvName) {
         auto [input, expectedName, expectedVersion] = GetParam();
-        const auto expr = fmt("builtins.parseDrvName \"%1%\"", input);
+        const auto expr = boostfmt("builtins.parseDrvName \"%1%\"", input);
         auto v = eval(expr);
         ASSERT_THAT(v, IsAttrsOfSize(2));
 

tests/unit/libmain/progress-bar.cc

@@ -32,7 +32,7 @@ namespace nix
             progressBar,
             lvlDebug,
             actFileTransfer,
-            fmt("downloading '%s'", TEST_URL),
+            boostfmt("downloading '%s'", TEST_URL),
             { "https://github.com/NixOS/nixpkgs/archive/master.tar.gz" }
         );
         act.progress(TEST_DONE, TEST_EXPECTED);

tests/unit/libstore/filetransfer.cc

@@ -156,7 +156,7 @@ TEST(FileTransfer, NOT_ON_DARWIN(reportsSetupErrors))
     auto [port, srv] = serveHTTP("404 not found", "", [] { return ""; });
     auto ft = makeFileTransfer();
     ASSERT_THROW(
-        ft->transfer(FileTransferRequest(fmt("http://[::1]:%d/index", port))),
+        ft->transfer(FileTransferRequest(boostfmt("http://[::1]:%d/index", port))),
         FileTransferError);
 }
 
@@ -171,7 +171,7 @@ TEST(FileTransfer, NOT_ON_DARWIN(defersFailures))
         return std::string(1024 * 1024, ' ');
     });
     auto ft = makeFileTransfer();
-    FileTransferRequest req(fmt("http://[::1]:%d/index", port));
+    FileTransferRequest req(boostfmt("http://[::1]:%d/index", port));
     req.baseRetryTimeMs = 0;
     auto src = ft->download(std::move(req));
     ASSERT_THROW(src->drain(), FileTransferError);
@@ -186,7 +186,7 @@ TEST(FileTransfer, NOT_ON_DARWIN(handlesContentEncoding))
     auto ft = makeFileTransfer();
 
     StringSink sink;
-    ft->download(FileTransferRequest(fmt("http://[::1]:%d/index", port)))->drainInto(sink);
+    ft->download(FileTransferRequest(boostfmt("http://[::1]:%d/index", port)))->drainInto(sink);
     EXPECT_EQ(sink.s, original);
 }
 
@@ -209,7 +209,7 @@ TEST(FileTransfer, usesIntermediateLinkHeaders)
         {"200 ok", "content-length: 1\r\n", [] { return "a"; }},
     });
     auto ft = makeFileTransfer();
-    FileTransferRequest req(fmt("http://[::1]:%d/first", port));
+    FileTransferRequest req(boostfmt("http://[::1]:%d/first", port));
     req.baseRetryTimeMs = 0;
     auto result = ft->transfer(req);
     ASSERT_EQ(result.immutableUrl, "http://foo");