Merge branch 'master' of github.com:NixOS/nix into templated-daemon-protocol

doc/manual/command-ref/conf-file.xml

@@ -370,6 +370,33 @@ false</literal>.</para>
 
   </varlistentry>
 
+  <varlistentry xml:id="conf-hashed-mirrors"><term><literal>hashed-mirrors</literal></term>
+
+    <listitem><para>A list of web servers used by
+    <function>builtins.fetchurl</function> to obtain files by hash.
+    Given a hash type <replaceable>ht</replaceable> and a base-16 hash
+    <replaceable>h</replaceable>, Nix will try to download the file
+    from
+    <literal>hashed-mirror/<replaceable>ht</replaceable>/<replaceable>h</replaceable></literal>.
+    This allows files to be downloaded even if they have disappeared
+    from their original URI. For example, given the hashed mirror
+    <literal>http://tarballs.example.com/</literal>, when building the
+    derivation
+
+<programlisting>
+builtins.fetchurl {
+  url = "https://example.org/foo-1.2.3.tar.xz";
+  sha256 = "2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae";
+}
+</programlisting>
+
+    Nix will attempt to download this file from
+    <literal>http://tarballs.example.com/sha256/2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae</literal>
+    first. If it is not available there, if will try the original URI.</para></listitem>
+
+  </varlistentry>
+
+
   <varlistentry xml:id="conf-http-connections"><term><literal>http-connections</literal></term>
 
     <listitem><para>The maximum number of parallel TCP connections

perl/lib/Nix/Store.xs

@@ -80,7 +80,7 @@ SV * queryReferences(char * path)
 SV * queryPathHash(char * path)
     PPCODE:
         try {
-            auto s = store()->queryPathInfo(store()->parseStorePath(path))->narHash->to_string(Base32, true);
+            auto s = store()->queryPathInfo(store()->parseStorePath(path))->narHash.to_string(Base32, true);
             XPUSHs(sv_2mortal(newSVpv(s.c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());
@@ -106,7 +106,7 @@ SV * queryPathInfo(char * path, int base32)
                 XPUSHs(&PL_sv_undef);
             else
                 XPUSHs(sv_2mortal(newSVpv(store()->printStorePath(*info->deriver).c_str(), 0)));
-            auto s = info->narHash->to_string(base32 ? Base32 : Base16, true);
+            auto s = info->narHash.to_string(base32 ? Base32 : Base16, true);
             XPUSHs(sv_2mortal(newSVpv(s.c_str(), 0)));
             mXPUSHi(info->registrationTime);
             mXPUSHi(info->narSize);
@@ -303,10 +303,10 @@ SV * derivationFromPath(char * drvPath)
             hash = newHV();
 
             HV * outputs = newHV();
-            for (auto & i : drv.outputs)
+            for (auto & i : drv.outputsAndPaths(*store()))
                 hv_store(
                     outputs, i.first.c_str(), i.first.size(),
-                    newSVpv(store()->printStorePath(i.second.path(*store(), drv.name)).c_str(), 0),
+                    newSVpv(store()->printStorePath(i.second.second).c_str(), 0),
                     0);
             hv_stores(hash, "outputs", newRV((SV *) outputs));
 

src/build-remote/build-remote.cc

@@ -38,9 +38,9 @@ static AutoCloseFD openSlotLock(const Machine & m, uint64_t slot)
     return openLockFile(fmt("%s/%s-%d", currentLoad, escapeUri(m.storeUri), slot), true);
 }
 
-static bool allSupportedLocally(const std::set<std::string>& requiredFeatures) {
+static bool allSupportedLocally(Store & store, const std::set<std::string>& requiredFeatures) {
     for (auto & feature : requiredFeatures)
-        if (!settings.systemFeatures.get().count(feature)) return false;
+        if (!store.systemFeatures.get().count(feature)) return false;
     return true;
 }
 
@@ -106,7 +106,7 @@ static int _main(int argc, char * * argv)
             auto canBuildLocally = amWilling
                  &&  (  neededSystem == settings.thisSystem
                      || settings.extraPlatforms.get().count(neededSystem) > 0)
-                 &&  allSupportedLocally(requiredFeatures);
+                 &&  allSupportedLocally(*store, requiredFeatures);
 
             /* Error ignored here, will be caught later */
             mkdir(currentLoad.c_str(), 0777);
@@ -201,7 +201,7 @@ static int _main(int argc, char * * argv)
                             % concatStringsSep<StringSet>(", ", m.mandatoryFeatures);
                         }
 
-                        logError({
+                        logErrorInfo(lvlInfo, {
                               .name = "Remote build",
                               .description = "Failed to find a machine for remote build!",
                               .hint = hint
@@ -224,15 +224,7 @@ static int _main(int argc, char * * argv)
 
                     Activity act(*logger, lvlTalkative, actUnknown, fmt("connecting to '%s'", bestMachine->storeUri));
 
-                    Store::Params storeParams;
+                    sshStore = bestMachine->openStore();
-                    if (hasPrefix(bestMachine->storeUri, "ssh://")) {
-                        storeParams["max-connections"] = "1";
-                        storeParams["log-fd"] = "4";
-                        if (bestMachine->sshKey != "")
-                            storeParams["ssh-key"] = bestMachine->sshKey;
-                    }
-
-                    sshStore = openStore(bestMachine->storeUri, storeParams);
                     sshStore->connect();
                     storeUri = bestMachine->storeUri;
 

src/libexpr/primops.cc

@@ -113,9 +113,9 @@ static void prim_scopedImport(EvalState & state, const Pos & pos, Value * * args
         state.mkList(*outputsVal, drv.outputs.size());
         unsigned int outputs_index = 0;
 
-        for (const auto & o : drv.outputs) {
+        for (const auto & o : drv.outputsAndPaths(*state.store)) {
             v2 = state.allocAttr(w, state.symbols.create(o.first));
-            mkString(*v2, state.store->printStorePath(o.second.path(*state.store, drv.name)), {"!" + o.first + "!" + path});
+            mkString(*v2, state.store->printStorePath(o.second.second), {"!" + o.first + "!" + path});
             outputsVal->listElems()[outputs_index] = state.allocValue();
             mkString(*(outputsVal->listElems()[outputs_index++]), o.first);
         }
@@ -781,7 +781,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
         Hash h = newHashAllowEmpty(*outputHash, ht);
 
         auto outPath = state.store->makeFixedOutputPath(ingestionMethod, h, drvName);
-        if (!jsonObject) drv.env["out"] = state.store->printStorePath(outPath);
+        drv.env["out"] = state.store->printStorePath(outPath);
         drv.outputs.insert_or_assign("out", DerivationOutput {
                 .output = DerivationOutputCAFixed {
                     .hash = FixedOutputHash {
@@ -795,7 +795,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
     else if (contentAddressed) {
         HashType ht = parseHashType(outputHashAlgo);
         for (auto & i : outputs) {
-            if (!jsonObject) drv.env[i] = hashPlaceholder(i);
+            drv.env[i] = hashPlaceholder(i);
             drv.outputs.insert_or_assign(i, DerivationOutput {
                 .output = DerivationOutputCAFloating {
                     .method = ingestionMethod,
@@ -813,7 +813,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
            that changes in the set of output names do get reflected in
            the hash. */
         for (auto & i : outputs) {
-            if (!jsonObject) drv.env[i] = "";
+            drv.env[i] = "";
             drv.outputs.insert_or_assign(i,
                 DerivationOutput {
                     .output = DerivationOutputInputAddressed {
@@ -828,7 +828,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
 
         for (auto & i : outputs) {
             auto outPath = state.store->makeOutputPath(i, h, drvName);
-            if (!jsonObject) drv.env[i] = state.store->printStorePath(outPath);
+            drv.env[i] = state.store->printStorePath(outPath);
             drv.outputs.insert_or_assign(i,
                 DerivationOutput {
                     .output = DerivationOutputInputAddressed {
@@ -839,7 +839,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
     }
 
     /* Write the resulting term into the Nix store directory. */
-    auto drvPath = writeDerivation(state.store, drv, drvName, state.repair);
+    auto drvPath = writeDerivation(state.store, drv, state.repair);
     auto drvPathS = state.store->printStorePath(drvPath);
 
     printMsg(lvlChatty, "instantiated '%1%' -> '%2%'", drvName, drvPathS);
@@ -852,9 +852,9 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
 
     state.mkAttrs(v, 1 + drv.outputs.size());
     mkString(*state.allocAttr(v, state.sDrvPath), drvPathS, {"=" + drvPathS});
-    for (auto & i : drv.outputs) {
+    for (auto & i : drv.outputsAndPaths(*state.store)) {
         mkString(*state.allocAttr(v, state.symbols.create(i.first)),
-            state.store->printStorePath(i.second.path(*state.store, drv.name)), {"!" + i.first + "!" + drvPathS});
+            state.store->printStorePath(i.second.second), {"!" + i.first + "!" + drvPathS});
     }
     v.attrs->sort();
 }

src/libexpr/primops/fetchTree.cc

@@ -212,7 +212,7 @@ static void fetch(EvalState & state, const Pos & pos, Value * * args, Value & v,
             : hashFile(htSHA256, path);
         if (hash != *expectedHash)
             throw Error((unsigned int) 102, "hash mismatch in file downloaded from '%s':\n  wanted: %s\n  got:    %s",
-                *url, expectedHash->to_string(Base32, true), hash->to_string(Base32, true));
+                *url, expectedHash->to_string(Base32, true), hash.to_string(Base32, true));
     }
 
     if (state.allowedPaths)

src/libfetchers/fetchers.cc

@@ -130,12 +130,12 @@ std::pair<Tree, Input> Input::fetch(ref<Store> store) const
         tree.actualPath = store->toRealPath(tree.storePath);
 
     auto narHash = store->queryPathInfo(tree.storePath)->narHash;
-    input.attrs.insert_or_assign("narHash", narHash->to_string(SRI, true));
+    input.attrs.insert_or_assign("narHash", narHash.to_string(SRI, true));
 
     if (auto prevNarHash = getNarHash()) {
         if (narHash != *prevNarHash)
             throw Error((unsigned int) 102, "NAR hash mismatch in input '%s' (%s), expected '%s', got '%s'",
-                to_string(), tree.actualPath, prevNarHash->to_string(SRI, true), narHash->to_string(SRI, true));
+                to_string(), tree.actualPath, prevNarHash->to_string(SRI, true), narHash.to_string(SRI, true));
     }
 
     if (auto prevLastModified = getLastModified()) {

src/libfetchers/git.cc

@@ -269,7 +269,7 @@ struct GitInputScheme : InputScheme
                 // modified dirty file?
                 input.attrs.insert_or_assign(
                     "lastModified",
-                    haveCommits ? std::stoull(runProgram("git", true, { "-C", actualUrl, "log", "-1", "--format=%ct", "HEAD" })) : 0);
+                    haveCommits ? std::stoull(runProgram("git", true, { "-C", actualUrl, "log", "-1", "--format=%ct", "--no-show-signature", "HEAD" })) : 0);
 
                 return {
                     Tree(store->printStorePath(storePath), std::move(storePath)),
@@ -421,7 +421,7 @@ struct GitInputScheme : InputScheme
 
         auto storePath = store->addToStore(name, tmpDir, FileIngestionMethod::Recursive, htSHA256, filter);
 
-        auto lastModified = std::stoull(runProgram("git", true, { "-C", repoDir, "log", "-1", "--format=%ct", input.getRev()->gitRev() }));
+        auto lastModified = std::stoull(runProgram("git", true, { "-C", repoDir, "log", "-1", "--format=%ct", "--no-show-signature", input.getRev()->gitRev() }));
 
         Attrs infoAttrs({
             {"rev", input.getRev()->gitRev()},

src/libfetchers/tarball.cc

@@ -67,8 +67,10 @@ DownloadFileResult downloadFile(
         StringSink sink;
         dumpString(*res.data, sink);
         auto hash = hashString(htSHA256, *res.data);
-        ValidPathInfo info(store->makeFixedOutputPath(FileIngestionMethod::Flat, hash, name));
+        ValidPathInfo info {
-        info.narHash = hashString(htSHA256, *sink.s);
+            store->makeFixedOutputPath(FileIngestionMethod::Flat, hash, name),
+            hashString(htSHA256, *sink.s),
+        };
         info.narSize = sink.s->size();
         info.ca = FixedOutputHash {
             .method = FileIngestionMethod::Flat,

src/libmain/progress-bar.cc

@@ -362,7 +362,7 @@ public:
         auto width = getWindowSize().second;
         if (width <= 0) width = std::numeric_limits<decltype(width)>::max();
 
-        writeToStderr("\r" + filterANSIEscapes(line, false, width) + "\e[K");
+        writeToStderr("\r" + filterANSIEscapes(line, false, width) + ANSI_NORMAL + "\e[K");
     }
 
     std::string getStatus(State & state)

src/libstore/binary-cache-store.cc

@@ -143,7 +143,7 @@ struct FileSource : FdSource
 void BinaryCacheStore::addToStore(const ValidPathInfo & info, Source & narSource,
     RepairFlag repair, CheckSigsFlag checkSigs)
 {
-    assert(info.narHash && info.narSize);
+    assert(info.narSize);
 
     if (!repair && isValidPath(info.path)) {
         // FIXME: copyNAR -> null sink
@@ -219,7 +219,7 @@ void BinaryCacheStore::addToStore(const ValidPathInfo & info, Source & narSource
             }
         }
 
-        upsertFile(std::string(info.path.to_string()) + ".ls", jsonOut.str(), "application/json");
+        upsertFile(std::string(info.path.hashPart()) + ".ls", jsonOut.str(), "application/json");
     }
 
     /* Optionally maintain an index of DWARF debug info files
@@ -312,14 +312,10 @@ void BinaryCacheStore::narFromPath(const StorePath & storePath, Sink & sink)
 {
     auto info = queryPathInfo(storePath).cast<const NarInfo>();
 
-    uint64_t narSize = 0;
+    LengthSink narSize;
+    TeeSink tee { sink, narSize };
 
-    LambdaSink wrapperSink([&](const unsigned char * data, size_t len) {
+    auto decompressor = makeDecompressionSink(info->compression, tee);
-        sink(data, len);
-        narSize += len;
-    });
-
-    auto decompressor = makeDecompressionSink(info->compression, wrapperSink);
 
     try {
         getFile(info->url, *decompressor);
@@ -331,7 +327,7 @@ void BinaryCacheStore::narFromPath(const StorePath & storePath, Sink & sink)
 
     stats.narRead++;
     //stats.narReadCompressedBytes += nar->size(); // FIXME
-    stats.narReadBytes += narSize;
+    stats.narReadBytes += narSize.length;
 }
 
 void BinaryCacheStore::queryPathInfoUncached(const StorePath & storePath,
@@ -385,7 +381,10 @@ StorePath BinaryCacheStore::addToStore(const string & name, const Path & srcPath
         h = hashString(hashAlgo, s);
     }
 
-    ValidPathInfo info(makeFixedOutputPath(method, *h, name));
+    ValidPathInfo info {
+        makeFixedOutputPath(method, *h, name),
+        Hash::dummy, // Will be fixed in addToStore, which recomputes nar hash
+    };
 
     auto source = StringSource { *sink.s };
     addToStore(info, source, repair, CheckSigs);
@@ -396,7 +395,10 @@ StorePath BinaryCacheStore::addToStore(const string & name, const Path & srcPath
 StorePath BinaryCacheStore::addTextToStore(const string & name, const string & s,
     const StorePathSet & references, RepairFlag repair)
 {
-    ValidPathInfo info(computeStorePathForText(name, s, references));
+    ValidPathInfo info {
+        computeStorePathForText(name, s, references),
+        Hash::dummy, // Will be fixed in addToStore, which recomputes nar hash
+    };
     info.references = references;
 
     if (repair || !isValidPath(info.path)) {

src/libstore/build.cc

@@ -1181,8 +1181,8 @@ void DerivationGoal::haveDerivation()
 
     retrySubstitution = false;
 
-    for (auto & i : drv->outputs)
+    for (auto & i : drv->outputsAndPaths(worker.store))
-        worker.store.addTempRoot(i.second.path(worker.store, drv->name));
+        worker.store.addTempRoot(i.second.second);
 
     /* Check what outputs paths are not already valid. */
     auto invalidOutputs = checkPathValidity(false, buildMode == bmRepair);
@@ -1288,14 +1288,14 @@ void DerivationGoal::repairClosure()
 
     /* Get the output closure. */
     StorePathSet outputClosure;
-    for (auto & i : drv->outputs) {
+    for (auto & i : drv->outputsAndPaths(worker.store)) {
         if (!wantOutput(i.first, wantedOutputs)) continue;
-        worker.store.computeFSClosure(i.second.path(worker.store, drv->name), outputClosure);
+        worker.store.computeFSClosure(i.second.second, outputClosure);
     }
 
     /* Filter out our own outputs (which we have already checked). */
-    for (auto & i : drv->outputs)
+    for (auto & i : drv->outputsAndPaths(worker.store))
-        outputClosure.erase(i.second.path(worker.store, drv->name));
+        outputClosure.erase(i.second.second);
 
     /* Get all dependencies of this derivation so that we know which
        derivation is responsible for which path in the output
@@ -1306,8 +1306,8 @@ void DerivationGoal::repairClosure()
     for (auto & i : inputClosure)
         if (i.isDerivation()) {
             Derivation drv = worker.store.derivationFromPath(i);
-            for (auto & j : drv.outputs)
+            for (auto & j : drv.outputsAndPaths(worker.store))
-                outputsToDrv.insert_or_assign(j.second.path(worker.store, drv.name), i);
+                outputsToDrv.insert_or_assign(j.second.second, i);
         }
 
     /* Check each path (slow!). */
@@ -1466,16 +1466,16 @@ void DerivationGoal::tryToBuild()
 
     /* If any of the outputs already exist but are not valid, delete
        them. */
-    for (auto & i : drv->outputs) {
+    for (auto & i : drv->outputsAndPaths(worker.store)) {
-        if (worker.store.isValidPath(i.second.path(worker.store, drv->name))) continue;
+        if (worker.store.isValidPath(i.second.second)) continue;
-        debug("removing invalid path '%s'", worker.store.printStorePath(i.second.path(worker.store, drv->name)));
+        debug("removing invalid path '%s'", worker.store.printStorePath(i.second.second));
-        deletePath(worker.store.Store::toRealPath(i.second.path(worker.store, drv->name)));
+        deletePath(worker.store.Store::toRealPath(i.second.second));
     }
 
     /* Don't do a remote build if the derivation has the attribute
        `preferLocalBuild' set.  Also, check and repair modes are only
        supported for local builds. */
-    bool buildLocally = buildMode != bmNormal || parsedDrv->willBuildLocally();
+    bool buildLocally = buildMode != bmNormal || parsedDrv->willBuildLocally(worker.store);
 
     /* Is the build hook willing to accept this job? */
     if (!buildLocally) {
@@ -1919,8 +1919,8 @@ StorePathSet DerivationGoal::exportReferences(const StorePathSet & storePaths)
     for (auto & j : paths2) {
         if (j.isDerivation()) {
             Derivation drv = worker.store.derivationFromPath(j);
-            for (auto & k : drv.outputs)
+            for (auto & k : drv.outputsAndPaths(worker.store))
-                worker.store.computeFSClosure(k.second.path(worker.store, drv.name), paths);
+                worker.store.computeFSClosure(k.second.second, paths);
         }
     }
 
@@ -1964,13 +1964,13 @@ void linkOrCopy(const Path & from, const Path & to)
 void DerivationGoal::startBuilder()
 {
     /* Right platform? */
-    if (!parsedDrv->canBuildLocally())
+    if (!parsedDrv->canBuildLocally(worker.store))
         throw Error("a '%s' with features {%s} is required to build '%s', but I am a '%s' with features {%s}",
             drv->platform,
             concatStringsSep(", ", parsedDrv->getRequiredSystemFeatures()),
             worker.store.printStorePath(drvPath),
             settings.thisSystem,
-            concatStringsSep<StringSet>(", ", settings.systemFeatures));
+            concatStringsSep<StringSet>(", ", worker.store.systemFeatures));
 
     if (drv->isBuiltin())
         preloadNSS();
@@ -2014,8 +2014,8 @@ void DerivationGoal::startBuilder()
     chownToBuilder(tmpDir);
 
     /* Substitute output placeholders with the actual output paths. */
-    for (auto & output : drv->outputs)
+    for (auto & output : drv->outputsAndPaths(worker.store))
-        inputRewrites[hashPlaceholder(output.first)] = worker.store.printStorePath(output.second.path(worker.store, drv->name));
+        inputRewrites[hashPlaceholder(output.first)] = worker.store.printStorePath(output.second.second);
 
     /* Construct the environment passed to the builder. */
     initEnv();
@@ -2199,8 +2199,8 @@ void DerivationGoal::startBuilder()
            rebuilding a path that is in settings.dirsInChroot
            (typically the dependencies of /bin/sh).  Throw them
            out. */
-        for (auto & i : drv->outputs)
+        for (auto & i : drv->outputsAndPaths(worker.store))
-            dirsInChroot.erase(worker.store.printStorePath(i.second.path(worker.store, drv->name)));
+            dirsInChroot.erase(worker.store.printStorePath(i.second.second));
 
 #elif __APPLE__
         /* We don't really have any parent prep work to do (yet?)
@@ -2612,8 +2612,8 @@ void DerivationGoal::writeStructuredAttrs()
 
     /* Add an "outputs" object containing the output paths. */
     nlohmann::json outputs;
-    for (auto & i : drv->outputs)
+    for (auto & i : drv->outputsAndPaths(worker.store))
-        outputs[i.first] = rewriteStrings(worker.store.printStorePath(i.second.path(worker.store, drv->name)), inputRewrites);
+        outputs[i.first] = rewriteStrings(worker.store.printStorePath(i.second.second), inputRewrites);
     json["outputs"] = outputs;
 
     /* Handle exportReferencesGraph. */
@@ -2819,9 +2819,9 @@ struct RestrictedStore : public LocalFSStore
                 if (!goal.isAllowed(path.path))
                     throw InvalidPath("cannot build unknown path '%s' in recursive Nix", printStorePath(path.path));
                 auto drv = derivationFromPath(path.path);
-                for (auto & output : drv.outputs)
+                for (auto & output : drv.outputsAndPaths(*this))
                     if (wantOutput(output.first, path.outputs))
-                        newPaths.insert(output.second.path(*this, drv.name));
+                        newPaths.insert(output.second.second);
             } else if (!goal.isAllowed(path.path))
                 throw InvalidPath("cannot build unknown path '%s' in recursive Nix", printStorePath(path.path));
         }
@@ -2924,7 +2924,8 @@ void DerivationGoal::startDaemon()
                 FdSink to(remote.get());
                 try {
                     daemon::processConnection(store, from, to,
-                        daemon::NotTrusted, daemon::Recursive, "nobody", 65535);
+                        daemon::NotTrusted, daemon::Recursive,
+                        [&](Store & store) { store.createUser("nobody", 65535); });
                     debug("terminated daemon connection");
                 } catch (SysError &) {
                     ignoreException();
@@ -3183,7 +3184,7 @@ void DerivationGoal::runChild()
                 createDirs(chrootRootDir + "/dev/shm");
                 createDirs(chrootRootDir + "/dev/pts");
                 ss.push_back("/dev/full");
-                if (settings.systemFeatures.get().count("kvm") && pathExists("/dev/kvm"))
+                if (worker.store.systemFeatures.get().count("kvm") && pathExists("/dev/kvm"))
                     ss.push_back("/dev/kvm");
                 ss.push_back("/dev/null");
                 ss.push_back("/dev/random");
@@ -3620,8 +3621,8 @@ void DerivationGoal::registerOutputs()
        to do anything here. */
     if (hook) {
         bool allValid = true;
-        for (auto & i : drv->outputs)
+        for (auto & i : drv->outputsAndPaths(worker.store))
-            if (!worker.store.isValidPath(i.second.path(worker.store, drv->name))) allValid = false;
+            if (!worker.store.isValidPath(i.second.second)) allValid = false;
         if (allValid) return;
     }
 
@@ -3642,23 +3643,23 @@ void DerivationGoal::registerOutputs()
        Nix calls. */
     StorePathSet referenceablePaths;
     for (auto & p : inputPaths) referenceablePaths.insert(p);
-    for (auto & i : drv->outputs) referenceablePaths.insert(i.second.path(worker.store, drv->name));
+    for (auto & i : drv->outputsAndPaths(worker.store)) referenceablePaths.insert(i.second.second);
     for (auto & p : addedPaths) referenceablePaths.insert(p);
 
     /* Check whether the output paths were created, and grep each
        output path to determine what other paths it references.  Also make all
        output paths read-only. */
-    for (auto & i : drv->outputs) {
+    for (auto & i : drv->outputsAndPaths(worker.store)) {
-        auto path = worker.store.printStorePath(i.second.path(worker.store, drv->name));
+        auto path = worker.store.printStorePath(i.second.second);
-        if (!missingPaths.count(i.second.path(worker.store, drv->name))) continue;
+        if (!missingPaths.count(i.second.second)) continue;
 
         Path actualPath = path;
         if (needsHashRewrite()) {
-            auto r = redirectedOutputs.find(i.second.path(worker.store, drv->name));
+            auto r = redirectedOutputs.find(i.second.second);
             if (r != redirectedOutputs.end()) {
                 auto redirected = worker.store.Store::toRealPath(r->second);
                 if (buildMode == bmRepair
-                    && redirectedBadOutputs.count(i.second.path(worker.store, drv->name))
+                    && redirectedBadOutputs.count(i.second.second)
                     && pathExists(redirected))
                     replaceValidPath(path, redirected);
                 if (buildMode == bmCheck)
@@ -3725,7 +3726,7 @@ void DerivationGoal::registerOutputs()
            hash). */
         std::optional<ContentAddress> ca;
 
-        if (! std::holds_alternative<DerivationOutputInputAddressed>(i.second.output)) {
+        if (! std::holds_alternative<DerivationOutputInputAddressed>(i.second.first.output)) {
             DerivationOutputCAFloating outputHash;
             std::visit(overloaded {
                 [&](DerivationOutputInputAddressed doi) {
@@ -3740,7 +3741,7 @@ void DerivationGoal::registerOutputs()
                 [&](DerivationOutputCAFloating dof) {
                     outputHash = dof;
                 },
-            }, i.second.output);
+            }, i.second.first.output);
 
             if (outputHash.method == FileIngestionMethod::Flat) {
                 /* The output path should be a regular file without execute permission. */
@@ -3757,12 +3758,12 @@ void DerivationGoal::registerOutputs()
                 ? hashPath(outputHash.hashType, actualPath).first
                 : hashFile(outputHash.hashType, actualPath);
 
-            auto dest = worker.store.makeFixedOutputPath(outputHash.method, h2, i.second.path(worker.store, drv->name).name());
+            auto dest = worker.store.makeFixedOutputPath(outputHash.method, h2, i.second.second.name());
 
             // true if either floating CA, or incorrect fixed hash.
             bool needsMove = true;
 
-            if (auto p = std::get_if<DerivationOutputCAFixed>(& i.second.output)) {
+            if (auto p = std::get_if<DerivationOutputCAFixed>(& i.second.first.output)) {
               Hash & h = p->hash.hash;
               if (h != h2) {
 
@@ -3868,8 +3869,10 @@ void DerivationGoal::registerOutputs()
             worker.markContentsGood(worker.store.parseStorePath(path));
         }
 
-        ValidPathInfo info(worker.store.parseStorePath(path));
+        ValidPathInfo info {
-        info.narHash = hash.first;
+            worker.store.parseStorePath(path),
+            hash.first,
+        };
         info.narSize = hash.second;
         info.references = std::move(references);
         info.deriver = drvPath;
@@ -3925,8 +3928,8 @@ void DerivationGoal::registerOutputs()
 
     /* If this is the first round of several, then move the output out of the way. */
     if (nrRounds > 1 && curRound == 1 && curRound < nrRounds && keepPreviousRound) {
-        for (auto & i : drv->outputs) {
+        for (auto & i : drv->outputsAndPaths(worker.store)) {
-            auto path = worker.store.printStorePath(i.second.path(worker.store, drv->name));
+            auto path = worker.store.printStorePath(i.second.second);
             Path prev = path + checkSuffix;
             deletePath(prev);
             Path dst = path + checkSuffix;
@@ -3943,8 +3946,8 @@ void DerivationGoal::registerOutputs()
     /* Remove the .check directories if we're done. FIXME: keep them
        if the result was not determistic? */
     if (curRound == nrRounds) {
-        for (auto & i : drv->outputs) {
+        for (auto & i : drv->outputsAndPaths(worker.store)) {
-            Path prev = worker.store.printStorePath(i.second.path(worker.store, drv->name)) + checkSuffix;
+            Path prev = worker.store.printStorePath(i.second.second) + checkSuffix;
             deletePath(prev);
         }
     }
@@ -4242,12 +4245,12 @@ void DerivationGoal::flushLine()
 StorePathSet DerivationGoal::checkPathValidity(bool returnValid, bool checkHash)
 {
     StorePathSet result;
-    for (auto & i : drv->outputs) {
+    for (auto & i : drv->outputsAndPaths(worker.store)) {
         if (!wantOutput(i.first, wantedOutputs)) continue;
         bool good =
-            worker.store.isValidPath(i.second.path(worker.store, drv->name)) &&
+            worker.store.isValidPath(i.second.second) &&
-            (!checkHash || worker.pathContentsGood(i.second.path(worker.store, drv->name)));
+            (!checkHash || worker.pathContentsGood(i.second.second));
-        if (good == returnValid) result.insert(i.second.path(worker.store, drv->name));
+        if (good == returnValid) result.insert(i.second.second);
     }
     return result;
 }
@@ -5074,7 +5077,7 @@ bool Worker::pathContentsGood(const StorePath & path)
     if (!pathExists(store.printStorePath(path)))
         res = false;
     else {
-        HashResult current = hashPath(info->narHash->type, store.printStorePath(path));
+        HashResult current = hashPath(info->narHash.type, store.printStorePath(path));
         Hash nullHash(htSHA256);
         res = info->narHash == nullHash || info->narHash == current.first;
     }

src/libstore/builtins/fetchurl.cc

@@ -58,6 +58,20 @@ void builtinFetchurl(const BasicDerivation & drv, const std::string & netrcData)
         }
     };
 
+    /* Try the hashed mirrors first. */
+    if (getAttr("outputHashMode") == "flat")
+        for (auto hashedMirror : settings.hashedMirrors.get())
+            try {
+                if (!hasSuffix(hashedMirror, "/")) hashedMirror += '/';
+                std::optional<HashType> ht = parseHashTypeOpt(getAttr("outputHashAlgo"));
+                Hash h = newHashAllowEmpty(getAttr("outputHash"), ht);
+                fetch(hashedMirror + printHashType(h.type) + "/" + h.to_string(Base16, false));
+                return;
+            } catch (Error & e) {
+                debug(e.what());
+            }
+
+    /* Otherwise try the specified URL. */
     fetch(mainUrl);
 }
 

src/libstore/daemon.cc

@@ -289,7 +289,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         logger->startWork();
         auto hash = store->queryPathInfo(path)->narHash;
         logger->stopWork();
-        to << hash->to_string(Base16, false);
+        to << hash.to_string(Base16, false);
         break;
     }
 
@@ -454,8 +454,46 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         readDerivation(from, *store, drv, Derivation::nameFromPath(drvPath));
         BuildMode buildMode = (BuildMode) readInt(from);
         logger->startWork();
-        if (!trusted)
+
-            throw Error("you are not privileged to build derivations");
+        /* Content-addressed derivations are trustless because their output paths
+           are verified by their content alone, so any derivation is free to
+           try to produce such a path.
+
+           Input-addressed derivation output paths, however, are calculated
+           from the derivation closure that produced them---even knowing the
+           root derivation is not enough. That the output data actually came
+           from those derivations is fundamentally unverifiable, but the daemon
+           trusts itself on that matter. The question instead is whether the
+           submitted plan has rights to the output paths it wants to fill, and
+           at least the derivation closure proves that.
+
+           It would have been nice if input-address algorithm merely depended
+           on the build time closure, rather than depending on the derivation
+           closure. That would mean input-addressed paths used at build time
+           would just be trusted and not need their own evidence. This is in
+           fact fine as the same guarantees would hold *inductively*: either
+           the remote builder has those paths and already trusts them, or it
+           needs to build them too and thus their evidence must be provided in
+           turn.  The advantage of this variant algorithm is that the evidence
+           for input-addressed paths which the remote builder already has
+           doesn't need to be sent again.
+
+           That said, now that we have floating CA derivations, it is better
+           that people just migrate to those which also solve this problem, and
+           others. It's the same migration difficulty with strictly more
+           benefit.
+
+           Lastly, do note that when we parse fixed-output content-addressed
+           derivations, we throw out the precomputed output paths and just
+           store the hashes, so there aren't two competing sources of truth an
+           attacker could exploit. */
+        if (drv.type() == DerivationType::InputAddressed && !trusted)
+            throw Error("you are not privileged to build input-addressed derivations");
+
+        /* Make sure that the non-input-addressed derivations that got this far
+           are in fact content-addressed if we don't trust them. */
+        assert(derivationIsCA(drv.type()) || trusted);
+
         auto res = store->buildDerivation(drvPath, drv, buildMode);
         logger->stopWork();
         to << res.status << res.errorMsg;
@@ -638,7 +676,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
             if (GET_PROTOCOL_MINOR(clientVersion) >= 17)
                 to << 1;
             to << (info->deriver ? store->printStorePath(*info->deriver) : "")
-               << info->narHash->to_string(Base16, false);
+               << info->narHash.to_string(Base16, false);
             WorkerProto<StorePathSet>::write(*store, to, info->references);
             to << info->registrationTime << info->narSize;
             if (GET_PROTOCOL_MINOR(clientVersion) >= 16) {
@@ -688,17 +726,18 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         auto path = store->parseStorePath(readString(from));
         logger->startWork();
         logger->stopWork();
-        dumpPath(store->printStorePath(path), to);
+        dumpPath(store->toRealPath(path), to);
         break;
     }
 
     case wopAddToStoreNar: {
         bool repair, dontCheckSigs;
-        ValidPathInfo info(store->parseStorePath(readString(from)));
+        auto path = store->parseStorePath(readString(from));
         auto deriver = readString(from);
+        auto narHash = Hash::parseAny(readString(from), htSHA256);
+        ValidPathInfo info { path, narHash };
         if (deriver != "")
             info.deriver = store->parseStorePath(deriver);
-        info.narHash = Hash::parseAny(readString(from), htSHA256);
         info.references = WorkerProto<StorePathSet>::read(*store, from);
         from >> info.registrationTime >> info.narSize >> info.ultimate;
         info.sigs = readStrings<StringSet>(from);
@@ -817,8 +856,7 @@ void processConnection(
     FdSink & to,
     TrustedFlag trusted,
     RecursiveFlag recursive,
-    const std::string & userName,
+    std::function<void(Store &)> authHook)
-    uid_t userId)
 {
     auto monitor = !recursive ? std::make_unique<MonitorFdHup>(from.fd) : nullptr;
 
@@ -859,15 +897,7 @@ void processConnection(
 
         /* If we can't accept clientVersion, then throw an error
            *here* (not above). */
-
+        authHook(*store);
-#if 0
-        /* Prevent users from doing something very dangerous. */
-        if (geteuid() == 0 &&
-            querySetting("build-users-group", "") == "")
-            throw Error("if you run 'nix-daemon' as root, then you MUST set 'build-users-group'!");
-#endif
-
-        store->createUser(userName, userId);
 
         tunnelLogger->stopWork();
         to.flush();

src/libstore/daemon.hh

@@ -12,7 +12,10 @@ void processConnection(
     FdSink & to,
     TrustedFlag trusted,
     RecursiveFlag recursive,
-    const std::string & userName,
+    /* Arbitrary hook to check authorization / initialize user data / whatever
-    uid_t userId);
+       after the protocol has been negotiated. The idea is that this function
+       and everything it calls doesn't know about this stuff, and the
+       `nix-daemon` handles that instead. */
+    std::function<void(Store &)> authHook);
 
 }

src/libstore/derivations.cc

@@ -62,7 +62,7 @@ bool BasicDerivation::isBuiltin() const
 
 
 StorePath writeDerivation(ref<Store> store,
-    const Derivation & drv, std::string_view name, RepairFlag repair)
+    const Derivation & drv, RepairFlag repair)
 {
     auto references = drv.inputSrcs;
     for (auto & i : drv.inputDrvs)
@@ -70,7 +70,7 @@ StorePath writeDerivation(ref<Store> store,
     /* Note that the outputs of a derivation are *not* references
        (that can be missing (of course) and should not necessarily be
        held during a garbage collection). */
-    auto suffix = std::string(name) + drvExtension;
+    auto suffix = std::string(drv.name) + drvExtension;
     auto contents = drv.unparse(*store, false);
     return settings.readOnlyMode
         ? store->computeStorePathForText(suffix, contents, references)
@@ -139,18 +139,14 @@ static StringSet parseStrings(std::istream & str, bool arePaths)
 }
 
 
-static DerivationOutput parseDerivationOutput(const Store & store, std::istringstream & str)
+static DerivationOutput parseDerivationOutput(const Store & store,
+    StorePath path, std::string_view hashAlgo, std::string_view hash)
 {
-    expect(str, ","); auto path = store.parseStorePath(parsePath(str));
-    expect(str, ","); auto hashAlgo = parseString(str);
-    expect(str, ","); const auto hash = parseString(str);
-    expect(str, ")");
-
     if (hashAlgo != "") {
         auto method = FileIngestionMethod::Flat;
         if (string(hashAlgo, 0, 2) == "r:") {
             method = FileIngestionMethod::Recursive;
-            hashAlgo = string(hashAlgo, 2);
+            hashAlgo = hashAlgo.substr(2);
         }
         const HashType hashType = parseHashType(hashAlgo);
 
@@ -178,6 +174,16 @@ static DerivationOutput parseDerivationOutput(const Store & store, std::istrings
         };
 }
 
+static DerivationOutput parseDerivationOutput(const Store & store, std::istringstream & str)
+{
+    expect(str, ","); auto path = store.parseStorePath(parsePath(str));
+    expect(str, ","); const auto hashAlgo = parseString(str);
+    expect(str, ","); const auto hash = parseString(str);
+    expect(str, ")");
+
+    return parseDerivationOutput(store, std::move(path), hashAlgo, hash);
+}
+
 
 static Derivation parseDerivation(const Store & store, std::string && s, std::string_view name)
 {
@@ -474,12 +480,12 @@ DrvHashModulo hashDerivationModulo(Store & store, const Derivation & drv, bool m
         throw Error("Regular input-addressed derivations are not yet allowed to depend on CA derivations");
     case DerivationType::CAFixed: {
         std::map<std::string, Hash> outputHashes;
-        for (const auto & i : drv.outputs) {
+        for (const auto & i : drv.outputsAndPaths(store)) {
-            auto & dof = std::get<DerivationOutputCAFixed>(i.second.output);
+            auto & dof = std::get<DerivationOutputCAFixed>(i.second.first.output);
             auto hash = hashString(htSHA256, "fixed:out:"
                 + dof.hash.printMethodAlgo() + ":"
                 + dof.hash.hash.to_string(Base16, false) + ":"
-                + store.printStorePath(i.second.path(store, drv.name)));
+                + store.printStorePath(i.second.second));
             outputHashes.insert_or_assign(i.first, std::move(hash));
         }
         return outputHashes;
@@ -533,46 +539,18 @@ bool wantOutput(const string & output, const std::set<string> & wanted)
 StorePathSet BasicDerivation::outputPaths(const Store & store) const
 {
     StorePathSet paths;
-    for (auto & i : outputs)
+    for (auto & i : outputsAndPaths(store))
-        paths.insert(i.second.path(store, name));
+        paths.insert(i.second.second);
     return paths;
 }
 
 static DerivationOutput readDerivationOutput(Source & in, const Store & store)
 {
     auto path = store.parseStorePath(readString(in));
-    auto hashAlgo = readString(in);
+    const auto hashAlgo = readString(in);
-    auto hash = readString(in);
+    const auto hash = readString(in);
 
-    if (hashAlgo != "") {
+    return parseDerivationOutput(store, std::move(path), hashAlgo, hash);
-        auto method = FileIngestionMethod::Flat;
-        if (string(hashAlgo, 0, 2) == "r:") {
-            method = FileIngestionMethod::Recursive;
-            hashAlgo = string(hashAlgo, 2);
-        }
-        auto hashType = parseHashType(hashAlgo);
-        return hash != ""
-            ? DerivationOutput {
-                  .output = DerivationOutputCAFixed {
-                      .hash = FixedOutputHash {
-                          .method = std::move(method),
-                          .hash = Hash::parseNonSRIUnprefixed(hash, hashType),
-                      },
-                  }
-               }
-            : (settings.requireExperimentalFeature("ca-derivations"),
-              DerivationOutput {
-                  .output = DerivationOutputCAFloating {
-                      .method = std::move(method),
-                      .hashType = std::move(hashType),
-                  },
-              });
-    } else
-        return DerivationOutput {
-            .output = DerivationOutputInputAddressed {
-                .path = std::move(path),
-            }
-        };
 }
 
 StringSet BasicDerivation::outputNames() const
@@ -583,6 +561,27 @@ StringSet BasicDerivation::outputNames() const
     return names;
 }
 
+DerivationOutputsAndPaths BasicDerivation::outputsAndPaths(const Store & store) const {
+    DerivationOutputsAndPaths outsAndPaths;
+    for (auto output : outputs)
+        outsAndPaths.insert(std::make_pair(
+            output.first,
+            std::make_pair(output.second, output.second.path(store, name))
+            )
+        );
+    return outsAndPaths;
+}
+
+DerivationOutputsAndOptPaths BasicDerivation::outputsAndOptPaths(const Store & store) const {
+    DerivationOutputsAndOptPaths outsAndOptPaths;
+    for (auto output : outputs)
+        outsAndOptPaths.insert(std::make_pair(
+            output.first,
+            std::make_pair(output.second, output.second.pathOpt(store, output.first))
+            )
+        );
+    return outsAndOptPaths;
+}
 
 std::string_view BasicDerivation::nameFromPath(const StorePath & drvPath) {
     auto nameWithSuffix = drvPath.name();
@@ -623,9 +622,9 @@ Source & readDerivation(Source & in, const Store & store, BasicDerivation & drv,
 void writeDerivation(Sink & out, const Store & store, const BasicDerivation & drv)
 {
     out << drv.outputs.size();
-    for (auto & i : drv.outputs) {
+    for (auto & i : drv.outputsAndPaths(store)) {
         out << i.first
-            << store.printStorePath(i.second.path(store, drv.name));
+            << store.printStorePath(i.second.second);
         std::visit(overloaded {
             [&](DerivationOutputInputAddressed doi) {
                 out << "" << "";
@@ -638,7 +637,7 @@ void writeDerivation(Sink & out, const Store & store, const BasicDerivation & dr
                 out << (makeFileIngestionPrefix(dof.method) + printHashType(dof.hashType))
                     << "";
             },
-        }, i.second.output);
+        }, i.second.first.output);
     }
     WorkerProto<StorePathSet>::write(store, out, drv.inputSrcs);
     out << drv.platform << drv.builder << drv.args;

src/libstore/derivations.hh

@@ -47,6 +47,9 @@ struct DerivationOutput
         DerivationOutputCAFloating
     > output;
     std::optional<HashType> hashAlgoOpt(const Store & store) const;
+    /* Note, when you use this function you should make sure that you're passing
+       the right derivation name. When in doubt, you should use the safer
+       interface provided by BasicDerivation::outputsAndPaths */
     std::optional<StorePath> pathOpt(const Store & store, std::string_view drvName) const;
     /* DEPRECATED: Remove after CA drvs are fully implemented */
     StorePath path(const Store & store, std::string_view drvName) const {
@@ -58,6 +61,15 @@ struct DerivationOutput
 
 typedef std::map<string, DerivationOutput> DerivationOutputs;
 
+/* These are analogues to the previous DerivationOutputs data type, but they
+   also contains, for each output, the (optional) store path in which it would
+   be written. To calculate values of these types, see the corresponding
+   functions in BasicDerivation */
+typedef std::map<string, std::pair<DerivationOutput, StorePath>>
+  DerivationOutputsAndPaths;
+typedef std::map<string, std::pair<DerivationOutput, std::optional<StorePath>>>
+  DerivationOutputsAndOptPaths;
+
 /* For inputs that are sub-derivations, we specify exactly which
    output IDs we are interested in. */
 typedef std::map<StorePath, StringSet> DerivationInputs;
@@ -107,6 +119,13 @@ struct BasicDerivation
     /* Return the output names of a derivation. */
     StringSet outputNames() const;
 
+    /* Calculates the maps that contains all the DerivationOutputs, but
+       augmented with knowledge of the Store paths they would be written into.
+       The first one of these functions will be removed when the CA work is
+       completed */
+    DerivationOutputsAndPaths outputsAndPaths(const Store & store) const;
+    DerivationOutputsAndOptPaths outputsAndOptPaths(const Store & store) const;
+
     static std::string_view nameFromPath(const StorePath & storePath);
 };
 
@@ -128,7 +147,7 @@ enum RepairFlag : bool { NoRepair = false, Repair = true };
 
 /* Write a derivation to the Nix store, and return its path. */
 StorePath writeDerivation(ref<Store> store,
-    const Derivation & drv, std::string_view name, RepairFlag repair = NoRepair);
+    const Derivation & drv, RepairFlag repair = NoRepair);
 
 /* Read a derivation from a file. */
 Derivation readDerivation(const Store & store, const Path & drvPath, std::string_view name);

src/libstore/export-import.cc

@@ -38,9 +38,9 @@ void Store::exportPath(const StorePath & path, Sink & sink)
        filesystem corruption from spreading to other machines.
        Don't complain if the stored hash is zero (unknown). */
     Hash hash = hashSink.currentHash().first;
-    if (hash != info->narHash && info->narHash != Hash(info->narHash->type))
+    if (hash != info->narHash && info->narHash != Hash(info->narHash.type))
         throw Error("hash of path '%s' has changed from '%s' to '%s'!",
-            printStorePath(path), info->narHash->to_string(Base32, true), hash.to_string(Base32, true));
+            printStorePath(path), info->narHash.to_string(Base32, true), hash.to_string(Base32, true));
 
     teeSink
         << exportMagic
@@ -69,17 +69,18 @@ StorePaths Store::importPaths(Source & source, CheckSigsFlag checkSigs)
         if (magic != exportMagic)
             throw Error("Nix archive cannot be imported; wrong format");
 
-        ValidPathInfo info(parseStorePath(readString(source)));
+        auto path = parseStorePath(readString(source));
 
         //Activity act(*logger, lvlInfo, format("importing path '%s'") % info.path);
 
-        info.references = WorkerProto<StorePathSet>::read(*this, source);
+        auto references = WorkerProto<StorePathSet>::read(*this, source);
-
         auto deriver = readString(source);
+        auto narHash = hashString(htSHA256, *saved.s);
+
+        ValidPathInfo info { path, narHash };
         if (deriver != "")
             info.deriver = parseStorePath(deriver);
-
+        info.references = references;
-        info.narHash = hashString(htSHA256, *saved.s);
         info.narSize = saved.s->size();
 
         // Ignore optional legacy signature.

src/libstore/globals.hh

@@ -335,6 +335,9 @@ public:
         "setuid/setgid bits or with file capabilities."};
 #endif
 
+    Setting<Strings> hashedMirrors{this, {}, "hashed-mirrors",
+        "A list of servers used by builtins.fetchurl to fetch files by hash."};
+
     Setting<uint64_t> minFree{this, 0, "min-free",
         "Automatically run the garbage collector when free disk space drops below the specified amount."};
 

src/libstore/legacy-ssh-store.cc

@@ -93,6 +93,9 @@ struct LegacySSHStore : public Store
         try {
             auto conn(connections->get());
 
+            /* No longer support missing NAR hash */
+            assert(GET_PROTOCOL_MINOR(conn->remoteVersion) >= 4);
+
             debug("querying remote host '%s' for info on '%s'", host, printStorePath(path));
 
             conn->to << cmdQueryPathInfos << PathSet{printStorePath(path)};
@@ -100,8 +103,10 @@ struct LegacySSHStore : public Store
 
             auto p = readString(conn->from);
             if (p.empty()) return callback(nullptr);
-            auto info = std::make_shared<ValidPathInfo>(parseStorePath(p));
+            auto path2 = parseStorePath(p);
-            assert(path == info->path);
+            assert(path == path2);
+            /* Hash will be set below. FIXME construct ValidPathInfo at end. */
+            auto info = std::make_shared<ValidPathInfo>(path, Hash::dummy);
 
             PathSet references;
             auto deriver = readString(conn->from);
@@ -111,12 +116,14 @@ struct LegacySSHStore : public Store
             readLongLong(conn->from); // download size
             info->narSize = readLongLong(conn->from);
 
-            if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 4) {
+            {
                 auto s = readString(conn->from);
-                info->narHash = s.empty() ? std::optional<Hash>{} : Hash::parseAnyPrefixed(s);
+                if (s == "")
+                    throw Error("NAR hash is now mandatory");
+                info->narHash = Hash::parseAnyPrefixed(s);
+            }
             info->ca = parseContentAddressOpt(readString(conn->from));
             info->sigs = readStrings<StringSet>(conn->from);
-            }
 
             auto s = readString(conn->from);
             assert(s == "");
@@ -138,7 +145,7 @@ struct LegacySSHStore : public Store
                 << cmdAddToStoreNar
                 << printStorePath(info.path)
                 << (info.deriver ? printStorePath(*info.deriver) : "")
-                << info.narHash->to_string(Base16, false);
+                << info.narHash.to_string(Base16, false);
             WorkerProto<StorePathSet>::write(*this, conn->to, info.references);
             conn->to
                 << info.registrationTime
@@ -202,6 +209,24 @@ struct LegacySSHStore : public Store
         const StorePathSet & references, RepairFlag repair) override
     { unsupported("addTextToStore"); }
 
+private:
+
+    void putBuildSettings(Connection & conn)
+    {
+        conn.to
+            << settings.maxSilentTime
+            << settings.buildTimeout;
+        if (GET_PROTOCOL_MINOR(conn.remoteVersion) >= 2)
+            conn.to
+                << settings.maxLogSize;
+        if (GET_PROTOCOL_MINOR(conn.remoteVersion) >= 3)
+            conn.to
+                << settings.buildRepeat
+                << settings.enforceDeterminism;
+    }
+
+public:
+
     BuildResult buildDerivation(const StorePath & drvPath, const BasicDerivation & drv,
         BuildMode buildMode) override
     {
@@ -211,16 +236,8 @@ struct LegacySSHStore : public Store
             << cmdBuildDerivation
             << printStorePath(drvPath);
         writeDerivation(conn->to, *this, drv);
-        conn->to
+
-            << settings.maxSilentTime
+        putBuildSettings(*conn);
-            << settings.buildTimeout;
-        if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 2)
-            conn->to
-                << settings.maxLogSize;
-        if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 3)
-            conn->to
-                << settings.buildRepeat
-                << settings.enforceDeterminism;
 
         conn->to.flush();
 
@@ -234,6 +251,29 @@ struct LegacySSHStore : public Store
         return status;
     }
 
+    void buildPaths(const std::vector<StorePathWithOutputs> & drvPaths, BuildMode buildMode) override
+    {
+        auto conn(connections->get());
+
+        conn->to << cmdBuildPaths;
+        Strings ss;
+        for (auto & p : drvPaths)
+            ss.push_back(p.to_string(*this));
+        conn->to << ss;
+
+        putBuildSettings(*conn);
+
+        conn->to.flush();
+
+        BuildResult result;
+        result.status = (BuildResult::Status) readInt(conn->from);
+
+        if (!result.success()) {
+            conn->from >> result.errorMsg;
+            throw Error(result.status, result.errorMsg);
+        }
+    }
+
     void ensurePath(const StorePath & path) override
     { unsupported("ensurePath"); }
 

src/libstore/local-store.cc

@@ -594,7 +594,7 @@ uint64_t LocalStore::addValidPath(State & state,
 
     state.stmtRegisterValidPath.use()
         (printStorePath(info.path))
-        (info.narHash->to_string(Base16, true))
+        (info.narHash.to_string(Base16, true))
         (info.registrationTime == 0 ? time(0) : info.registrationTime)
         (info.deriver ? printStorePath(*info.deriver) : "", (bool) info.deriver)
         (info.narSize, info.narSize != 0)
@@ -618,11 +618,11 @@ uint64_t LocalStore::addValidPath(State & state,
            registration above is undone. */
         if (checkOutputs) checkDerivationOutputs(info.path, drv);
 
-        for (auto & i : drv.outputs) {
+        for (auto & i : drv.outputsAndPaths(*this)) {
             state.stmtAddDerivationOutput.use()
                 (id)
                 (i.first)
-                (printStorePath(i.second.path(*this, drv.name)))
+                (printStorePath(i.second.second))
                 .exec();
         }
     }
@@ -641,25 +641,28 @@ void LocalStore::queryPathInfoUncached(const StorePath & path,
     Callback<std::shared_ptr<const ValidPathInfo>> callback) noexcept
 {
     try {
-        auto info = std::make_shared<ValidPathInfo>(path);
-
         callback(retrySQLite<std::shared_ptr<ValidPathInfo>>([&]() {
             auto state(_state.lock());
 
             /* Get the path info. */
-            auto useQueryPathInfo(state->stmtQueryPathInfo.use()(printStorePath(info->path)));
+            auto useQueryPathInfo(state->stmtQueryPathInfo.use()(printStorePath(path)));
 
             if (!useQueryPathInfo.next())
                 return std::shared_ptr<ValidPathInfo>();
 
-            info->id = useQueryPathInfo.getInt(0);
+            auto id = useQueryPathInfo.getInt(0);
 
+            auto narHash = Hash::dummy;
             try {
-                info->narHash = Hash::parseAnyPrefixed(useQueryPathInfo.getStr(1));
+                narHash = Hash::parseAnyPrefixed(useQueryPathInfo.getStr(1));
             } catch (BadHash & e) {
                 throw Error("invalid-path entry for '%s': %s", printStorePath(path), e.what());
             }
 
+            auto info = std::make_shared<ValidPathInfo>(path, narHash);
+
+            info->id = id;
+
             info->registrationTime = useQueryPathInfo.getInt(2);
 
             auto s = (const char *) sqlite3_column_text(state->stmtQueryPathInfo, 3);
@@ -694,7 +697,7 @@ void LocalStore::updatePathInfo(State & state, const ValidPathInfo & info)
 {
     state.stmtUpdatePathInfo.use()
         (info.narSize, info.narSize != 0)
-        (info.narHash->to_string(Base16, true))
+        (info.narHash.to_string(Base16, true))
         (info.ultimate ? 1 : 0, info.ultimate)
         (concatStringsSep(" ", info.sigs), !info.sigs.empty())
         (renderContentAddress(info.ca), (bool) info.ca)
@@ -924,7 +927,7 @@ void LocalStore::registerValidPaths(const ValidPathInfos & infos)
         StorePathSet paths;
 
         for (auto & i : infos) {
-            assert(i.narHash && i.narHash->type == htSHA256);
+            assert(i.narHash.type == htSHA256);
             if (isValidPath_(*state, i.path))
                 updatePathInfo(*state, i);
             else
@@ -988,9 +991,6 @@ const PublicKeys & LocalStore::getPublicKeys()
 void LocalStore::addToStore(const ValidPathInfo & info, Source & source,
     RepairFlag repair, CheckSigsFlag checkSigs)
 {
-    if (!info.narHash)
-        throw Error("cannot add path '%s' because it lacks a hash", printStorePath(info.path));
-
     if (requireSigs && checkSigs && !info.checkSignatures(*this, getPublicKeys()))
         throw Error("cannot add path '%s' because it lacks a valid signature", printStorePath(info.path));
 
@@ -1025,11 +1025,7 @@ void LocalStore::addToStore(const ValidPathInfo & info, Source & source,
             else
                 hashSink = std::make_unique<HashModuloSink>(htSHA256, std::string(info.path.hashPart()));
 
-            LambdaSource wrapperSource([&](unsigned char * data, size_t len) -> size_t {
+            TeeSource wrapperSource { source, *hashSink };
-                size_t n = source.read(data, len);
-                (*hashSink)(data, n);
-                return n;
-            });
 
             restorePath(realPath, wrapperSource);
 
@@ -1037,7 +1033,7 @@ void LocalStore::addToStore(const ValidPathInfo & info, Source & source,
 
             if (hashResult.first != info.narHash)
                 throw Error("hash mismatch importing path '%s';\n  wanted: %s\n  got:    %s",
-                    printStorePath(info.path), info.narHash->to_string(Base32, true), hashResult.first.to_string(Base32, true));
+                    printStorePath(info.path), info.narHash.to_string(Base32, true), hashResult.first.to_string(Base32, true));
 
             if (hashResult.second != info.narSize)
                 throw Error("size mismatch importing path '%s';\n  wanted: %s\n  got:   %s",
@@ -1159,8 +1155,7 @@ StorePath LocalStore::addToStoreFromDump(Source & source0, const string & name,
 
             optimisePath(realPath);
 
-            ValidPathInfo info(dstPath);
+            ValidPathInfo info { dstPath, narHash.first };
-            info.narHash = narHash.first;
             info.narSize = narHash.second;
             info.ca = FixedOutputHash { .method = method, .hash = hash };
             registerValidPath(info);
@@ -1203,8 +1198,7 @@ StorePath LocalStore::addTextToStore(const string & name, const string & s,
 
             optimisePath(realPath);
 
-            ValidPathInfo info(dstPath);
+            ValidPathInfo info { dstPath, narHash };
-            info.narHash = narHash;
             info.narSize = sink.s->size();
             info.references = references;
             info.ca = TextHash { .hash = hash };
@@ -1319,9 +1313,9 @@ bool LocalStore::verifyStore(bool checkContents, RepairFlag repair)
 
                 std::unique_ptr<AbstractHashSink> hashSink;
                 if (!info->ca || !info->references.count(info->path))
-                    hashSink = std::make_unique<HashSink>(info->narHash->type);
+                    hashSink = std::make_unique<HashSink>(info->narHash.type);
                 else
-                    hashSink = std::make_unique<HashModuloSink>(info->narHash->type, std::string(info->path.hashPart()));
+                    hashSink = std::make_unique<HashModuloSink>(info->narHash.type, std::string(info->path.hashPart()));
 
                 dumpPath(Store::toRealPath(i), *hashSink);
                 auto current = hashSink->finish();
@@ -1330,7 +1324,7 @@ bool LocalStore::verifyStore(bool checkContents, RepairFlag repair)
                     logError({
                         .name = "Invalid hash - path modified",
                         .hint = hintfmt("path '%s' was modified! expected hash '%s', got '%s'",
-                        printStorePath(i), info->narHash->to_string(Base32, true), current.first.to_string(Base32, true))
+                        printStorePath(i), info->narHash.to_string(Base32, true), current.first.to_string(Base32, true))
                     });
                     if (repair) repairPath(i); else errors = true;
                 } else {

src/libstore/machines.cc

@@ -1,6 +1,7 @@
 #include "machines.hh"
 #include "util.hh"
 #include "globals.hh"
+#include "store-api.hh"
 
 #include <algorithm>
 
@@ -48,6 +49,29 @@ bool Machine::mandatoryMet(const std::set<string> & features) const {
         });
 }
 
+ref<Store> Machine::openStore() const {
+    Store::Params storeParams;
+    if (hasPrefix(storeUri, "ssh://")) {
+        storeParams["max-connections"] = "1";
+        storeParams["log-fd"] = "4";
+        if (sshKey != "")
+            storeParams["ssh-key"] = sshKey;
+    }
+    {
+        auto & fs = storeParams["system-features"];
+        auto append = [&](auto feats) {
+            for (auto & f : feats) {
+                if (fs.size() > 0) fs += ' ';
+                fs += f;
+            }
+        };
+        append(supportedFeatures);
+        append(mandatoryFeatures);
+    }
+
+    return nix::openStore(storeUri, storeParams);
+}
+
 void parseMachines(const std::string & s, Machines & machines)
 {
     for (auto line : tokenizeString<std::vector<string>>(s, "\n;")) {

src/libstore/machines.hh

@@ -4,6 +4,8 @@
 
 namespace nix {
 
+class Store;
+
 struct Machine {
 
     const string storeUri;
@@ -28,6 +30,8 @@ struct Machine {
         decltype(supportedFeatures) supportedFeatures,
         decltype(mandatoryFeatures) mandatoryFeatures,
         decltype(sshPublicHostKey) sshPublicHostKey);
+
+    ref<Store> openStore() const;
 };
 
 typedef std::vector<Machine> Machines;

src/libstore/misc.cc

@@ -207,10 +207,10 @@ void Store::queryMissing(const std::vector<StorePathWithOutputs> & targets,
             ParsedDerivation parsedDrv(StorePath(path.path), *drv);
 
             PathSet invalid;
-            for (auto & j : drv->outputs)
+            for (auto & j : drv->outputsAndPaths(*this))
                 if (wantOutput(j.first, path.outputs)
-                    && !isValidPath(j.second.path(*this, drv->name)))
+                    && !isValidPath(j.second.second))
-                    invalid.insert(printStorePath(j.second.path(*this, drv->name)));
+                    invalid.insert(printStorePath(j.second.second));
             if (invalid.empty()) return;
 
             if (settings.useSubstitutes && parsedDrv.substitutesAllowed()) {

src/libstore/nar-info-disk-cache.cc

@@ -189,13 +189,14 @@ public:
                 return {oInvalid, 0};
 
             auto namePart = queryNAR.getStr(1);
-            auto narInfo = make_ref<NarInfo>(StorePath(hashPart + "-" + namePart));
+            auto narInfo = make_ref<NarInfo>(
+                StorePath(hashPart + "-" + namePart),
+                Hash::parseAnyPrefixed(queryNAR.getStr(6)));
             narInfo->url = queryNAR.getStr(2);
             narInfo->compression = queryNAR.getStr(3);
             if (!queryNAR.isNull(4))
                 narInfo->fileHash = Hash::parseAnyPrefixed(queryNAR.getStr(4));
             narInfo->fileSize = queryNAR.getInt(5);
-            narInfo->narHash = Hash::parseAnyPrefixed(queryNAR.getStr(6));
             narInfo->narSize = queryNAR.getInt(7);
             for (auto & r : tokenizeString<Strings>(queryNAR.getStr(8), " "))
                 narInfo->references.insert(StorePath(r));
@@ -232,7 +233,7 @@ public:
                     (narInfo ? narInfo->compression : "", narInfo != 0)
                     (narInfo && narInfo->fileHash ? narInfo->fileHash->to_string(Base32, true) : "", narInfo && narInfo->fileHash)
                     (narInfo ? narInfo->fileSize : 0, narInfo != 0 && narInfo->fileSize)
-                    (info->narHash->to_string(Base32, true))
+                    (info->narHash.to_string(Base32, true))
                     (info->narSize)
                     (concatStringsSep(" ", info->shortRefs()))
                     (info->deriver ? std::string(info->deriver->to_string()) : "", (bool) info->deriver)

src/libstore/nar-info.cc

@@ -1,10 +1,11 @@
 #include "globals.hh"
 #include "nar-info.hh"
+#include "store-api.hh"
 
 namespace nix {
 
 NarInfo::NarInfo(const Store & store, const std::string & s, const std::string & whence)
-    : ValidPathInfo(StorePath(StorePath::dummy)) // FIXME: hack
+    : ValidPathInfo(StorePath(StorePath::dummy), Hash(Hash::dummy)) // FIXME: hack
 {
     auto corrupt = [&]() {
         return Error("NAR info file '%1%' is corrupt", whence);
@@ -19,6 +20,7 @@ NarInfo::NarInfo(const Store & store, const std::string & s, const std::string &
     };
 
     bool havePath = false;
+    bool haveNarHash = false;
 
     size_t pos = 0;
     while (pos < s.size()) {
@@ -46,8 +48,10 @@ NarInfo::NarInfo(const Store & store, const std::string & s, const std::string &
         else if (name == "FileSize") {
             if (!string2Int(value, fileSize)) throw corrupt();
         }
-        else if (name == "NarHash")
+        else if (name == "NarHash") {
             narHash = parseHashField(value);
+            haveNarHash = true;
+        }
         else if (name == "NarSize") {
             if (!string2Int(value, narSize)) throw corrupt();
         }
@@ -76,7 +80,7 @@ NarInfo::NarInfo(const Store & store, const std::string & s, const std::string &
 
     if (compression == "") compression = "bzip2";
 
-    if (!havePath || url.empty() || narSize == 0 || !narHash) throw corrupt();
+    if (!havePath || !haveNarHash || url.empty() || narSize == 0) throw corrupt();
 }
 
 std::string NarInfo::to_string(const Store & store) const
@@ -89,8 +93,8 @@ std::string NarInfo::to_string(const Store & store) const
     assert(fileHash && fileHash->type == htSHA256);
     res += "FileHash: " + fileHash->to_string(Base32, true) + "\n";
     res += "FileSize: " + std::to_string(fileSize) + "\n";
-    assert(narHash && narHash->type == htSHA256);
+    assert(narHash.type == htSHA256);
-    res += "NarHash: " + narHash->to_string(Base32, true) + "\n";
+    res += "NarHash: " + narHash.to_string(Base32, true) + "\n";
     res += "NarSize: " + std::to_string(narSize) + "\n";
 
     res += "References: " + concatStringsSep(" ", shortRefs()) + "\n";

src/libstore/nar-info.hh

@@ -2,10 +2,12 @@
 
 #include "types.hh"
 #include "hash.hh"
-#include "store-api.hh"
+#include "path-info.hh"
 
 namespace nix {
 
+class Store;
+
 struct NarInfo : ValidPathInfo
 {
     std::string url;
@@ -15,7 +17,7 @@ struct NarInfo : ValidPathInfo
     std::string system;
 
     NarInfo() = delete;
-    NarInfo(StorePath && path) : ValidPathInfo(std::move(path)) { }
+    NarInfo(StorePath && path, Hash narHash) : ValidPathInfo(std::move(path), narHash) { }
     NarInfo(const ValidPathInfo & info) : ValidPathInfo(info) { }
     NarInfo(const Store & store, const std::string & s, const std::string & whence);
 

src/libstore/parsed-derivations.cc

@@ -94,7 +94,7 @@ StringSet ParsedDerivation::getRequiredSystemFeatures() const
     return res;
 }
 
-bool ParsedDerivation::canBuildLocally() const
+bool ParsedDerivation::canBuildLocally(Store & localStore) const
 {
     if (drv.platform != settings.thisSystem.get()
         && !settings.extraPlatforms.get().count(drv.platform)
@@ -102,14 +102,14 @@ bool ParsedDerivation::canBuildLocally() const
         return false;
 
     for (auto & feature : getRequiredSystemFeatures())
-        if (!settings.systemFeatures.get().count(feature)) return false;
+        if (!localStore.systemFeatures.get().count(feature)) return false;
 
     return true;
 }
 
-bool ParsedDerivation::willBuildLocally() const
+bool ParsedDerivation::willBuildLocally(Store & localStore) const
 {
-    return getBoolAttr("preferLocalBuild") && canBuildLocally();
+    return getBoolAttr("preferLocalBuild") && canBuildLocally(localStore);
 }
 
 bool ParsedDerivation::substitutesAllowed() const

src/libstore/parsed-derivations.hh

@@ -29,9 +29,9 @@ public:
 
     StringSet getRequiredSystemFeatures() const;
 
-    bool canBuildLocally() const;
+    bool canBuildLocally(Store & localStore) const;
 
-    bool willBuildLocally() const;
+    bool willBuildLocally(Store & localStore) const;
 
     bool substitutesAllowed() const;
 };

src/libstore/path-info.hh

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "crypto.hh"
 #include "path.hh"
 #include "hash.hh"
 #include "content-address.hh"
@@ -29,7 +30,7 @@ struct ValidPathInfo
     StorePath path;
     std::optional<StorePath> deriver;
     // TODO document this
-    std::optional<Hash> narHash;
+    Hash narHash;
     StorePathSet references;
     time_t registrationTime = 0;
     uint64_t narSize = 0; // 0 = unknown
@@ -100,8 +101,8 @@ struct ValidPathInfo
 
     ValidPathInfo(const ValidPathInfo & other) = default;
 
-    ValidPathInfo(StorePath && path) : path(std::move(path)) { };
+    ValidPathInfo(StorePath && path, Hash narHash) : path(std::move(path)), narHash(narHash) { };
-    ValidPathInfo(const StorePath & path) : path(path) { };
+    ValidPathInfo(const StorePath & path, Hash narHash) : path(path), narHash(narHash) { };
 
     virtual ~ValidPathInfo() { }
 };

src/libstore/remote-store.cc

@@ -416,10 +416,10 @@ void RemoteStore::queryPathInfoUncached(const StorePath & path,
                 bool valid; conn->from >> valid;
                 if (!valid) throw InvalidPath("path '%s' is not valid", printStorePath(path));
             }
-            info = std::make_shared<ValidPathInfo>(StorePath(path));
             auto deriver = readString(conn->from);
+            auto narHash = Hash::parseAny(readString(conn->from), htSHA256);
+            info = std::make_shared<ValidPathInfo>(path, narHash);
             if (deriver != "") info->deriver = parseStorePath(deriver);
-            info->narHash = Hash::parseAny(readString(conn->from), htSHA256);
             info->references = WorkerProto<StorePathSet>::read(*this, conn->from);
             conn->from >> info->registrationTime >> info->narSize;
             if (GET_PROTOCOL_MINOR(conn->daemonVersion) >= 16) {
@@ -517,7 +517,7 @@ void RemoteStore::addToStore(const ValidPathInfo & info, Source & source,
         conn->to << wopAddToStoreNar
                  << printStorePath(info.path)
                  << (info.deriver ? printStorePath(*info.deriver) : "")
-                 << info.narHash->to_string(Base16, false);
+                 << info.narHash.to_string(Base16, false);
         WorkerProto<StorePathSet>::write(*this, conn->to, info.references);
         conn->to << info.registrationTime << info.narSize
                  << info.ultimate << info.sigs << renderContentAddress(info.ca)

src/libstore/store-api.cc

@@ -320,8 +320,10 @@ ValidPathInfo Store::addToStoreSlow(std::string_view name, const Path & srcPath,
     if (expectedCAHash && expectedCAHash != hash)
         throw Error("hash mismatch for '%s'", srcPath);
 
-    ValidPathInfo info(makeFixedOutputPath(method, hash, name));
+    ValidPathInfo info {
-    info.narHash = narHash;
+        makeFixedOutputPath(method, hash, name),
+        narHash,
+    };
     info.narSize = narSize;
     info.ca = FixedOutputHash { .method = method, .hash = hash };
 
@@ -576,7 +578,7 @@ string Store::makeValidityRegistration(const StorePathSet & paths,
         auto info = queryPathInfo(i);
 
         if (showHash) {
-            s += info->narHash->to_string(Base16, false) + "\n";
+            s += info->narHash.to_string(Base16, false) + "\n";
             s += (format("%1%\n") % info->narSize).str();
         }
 
@@ -608,7 +610,7 @@ void Store::pathInfoToJSON(JSONPlaceholder & jsonOut, const StorePathSet & store
             auto info = queryPathInfo(storePath);
 
             jsonPath
-                .attr("narHash", info->narHash->to_string(hashBase, true))
+                .attr("narHash", info->narHash.to_string(hashBase, true))
                 .attr("narSize", info->narSize);
 
             {
@@ -736,20 +738,6 @@ void copyStorePath(ref<Store> srcStore, ref<Store> dstStore,
         info = info2;
     }
 
-    if (!info->narHash) {
-        StringSink sink;
-        srcStore->narFromPath({storePath}, sink);
-        auto info2 = make_ref<ValidPathInfo>(*info);
-        info2->narHash = hashString(htSHA256, *sink.s);
-        if (!info->narSize) info2->narSize = sink.s->size();
-        if (info->ultimate) info2->ultimate = false;
-        info = info2;
-
-        StringSource source(*sink.s);
-        dstStore->addToStore(*info, source, repair, checkSigs);
-        return;
-    }
-
     if (info->ultimate) {
         auto info2 = make_ref<ValidPathInfo>(*info);
         info2->ultimate = false;
@@ -757,12 +745,12 @@ void copyStorePath(ref<Store> srcStore, ref<Store> dstStore,
     }
 
     auto source = sinkToSource([&](Sink & sink) {
-        LambdaSink wrapperSink([&](const unsigned char * data, size_t len) {
+        LambdaSink progressSink([&](const unsigned char * data, size_t len) {
-            sink(data, len);
             total += len;
             act.progress(total, info->narSize);
         });
-        srcStore->narFromPath(storePath, wrapperSink);
+        TeeSink tee { sink, progressSink };
+        srcStore->narFromPath(storePath, tee);
     }, [&]() {
            throw EndOfFile("NAR for '%s' fetched from '%s' is incomplete", srcStore->printStorePath(storePath), srcStore->getUri());
     });
@@ -874,19 +862,22 @@ void copyClosure(ref<Store> srcStore, ref<Store> dstStore,
 }
 
 
-std::optional<ValidPathInfo> decodeValidPathInfo(const Store & store, std::istream & str, bool hashGiven)
+std::optional<ValidPathInfo> decodeValidPathInfo(const Store & store, std::istream & str, std::optional<HashResult> hashGiven)
 {
     std::string path;
     getline(str, path);
     if (str.eof()) { return {}; }
-    ValidPathInfo info(store.parseStorePath(path));
+    if (!hashGiven) {
-    if (hashGiven) {
         string s;
         getline(str, s);
-        info.narHash = Hash::parseAny(s, htSHA256);
+        auto narHash = Hash::parseAny(s, htSHA256);
         getline(str, s);
-        if (!string2Int(s, info.narSize)) throw Error("number expected");
+        uint64_t narSize;
+        if (!string2Int(s, narSize)) throw Error("number expected");
+        hashGiven = { narHash, narSize };
     }
+    ValidPathInfo info(store.parseStorePath(path), hashGiven->first);
+    info.narSize = hashGiven->second;
     std::string deriver;
     getline(str, deriver);
     if (deriver != "") info.deriver = store.parseStorePath(deriver);
@@ -921,12 +912,12 @@ string showPaths(const PathSet & paths)
 
 std::string ValidPathInfo::fingerprint(const Store & store) const
 {
-    if (narSize == 0 || !narHash)
+    if (narSize == 0)
-        throw Error("cannot calculate fingerprint of path '%s' because its size/hash is not known",
+        throw Error("cannot calculate fingerprint of path '%s' because its size is not known",
             store.printStorePath(path));
     return
         "1;" + store.printStorePath(path) + ";"
-        + narHash->to_string(Base32, true) + ";"
+        + narHash.to_string(Base32, true) + ";"
         + std::to_string(narSize) + ";"
         + concatStringsSep(",", store.printStorePathSet(references));
 }

src/libstore/store-api.hh

@@ -4,7 +4,6 @@
 #include "hash.hh"
 #include "content-address.hh"
 #include "serialise.hh"
-#include "crypto.hh"
 #include "lru-cache.hh"
 #include "sync.hh"
 #include "globals.hh"
@@ -164,6 +163,10 @@ public:
 
     Setting<bool> wantMassQuery{this, false, "want-mass-query", "whether this substituter can be queried efficiently for path validity"};
 
+    Setting<StringSet> systemFeatures{this, settings.systemFeatures,
+        "system-features",
+        "Optional features that the system this store builds on implements (like \"kvm\")."};
+
 protected:
 
     struct PathInfoCacheValue {
@@ -767,7 +770,7 @@ string showPaths(const PathSet & paths);
 std::optional<ValidPathInfo> decodeValidPathInfo(
     const Store & store,
     std::istream & str,
-    bool hashGiven = false);
+    std::optional<HashResult> hashGiven = std::nullopt);
 
 /* Split URI into protocol+hierarchy part and its parameter set. */
 std::pair<std::string, Store::Params> splitUriAndParams(const std::string & uri);

src/libstore/worker-protocol.hh

@@ -6,7 +6,7 @@ namespace nix {
 #define WORKER_MAGIC_1 0x6e697863
 #define WORKER_MAGIC_2 0x6478696f
 
-#define PROTOCOL_VERSION 0x117
+#define PROTOCOL_VERSION 0x118
 #define GET_PROTOCOL_MAJOR(x) ((x) & 0xff00)
 #define GET_PROTOCOL_MINOR(x) ((x) & 0x00ff)
 

src/libutil/archive.cc

@@ -366,11 +366,7 @@ void copyNAR(Source & source, Sink & sink)
 
     ParseSink parseSink; /* null sink; just parse the NAR */
 
-    LambdaSource wrapper([&](unsigned char * data, size_t len) {
+    TeeSource wrapper { source, sink };
-        auto n = source.read(data, len);
-        sink(data, n);
-        return n;
-    });
 
     parseDump(parseSink, wrapper);
 }

src/libutil/hash.cc

@@ -136,6 +136,8 @@ std::string Hash::to_string(Base base, bool includeType) const
     return s;
 }
 
+Hash Hash::dummy(htSHA256);
+
 Hash Hash::parseSRI(std::string_view original) {
     auto rest = original;
 

src/libutil/hash.hh

@@ -59,9 +59,6 @@ private:
     Hash(std::string_view s, HashType type, bool isSRI);
 
 public:
-    /* Check whether a hash is set. */
-    operator bool () const { return (bool) type; }
-
     /* Check whether two hash are equal. */
     bool operator == (const Hash & h2) const;
 
@@ -105,6 +102,8 @@ public:
         assert(type == htSHA1);
         return std::string(to_string(Base16, false), 0, 7);
     }
+
+    static Hash dummy;
 };
 
 /* Helper that defaults empty hashes to the 0 hash. */

src/libutil/serialise.hh

@@ -225,6 +225,17 @@ struct SizedSource : Source
     }
 };
 
+/* A sink that that just counts the number of bytes given to it */
+struct LengthSink : Sink
+{
+    uint64_t length = 0;
+
+    virtual void operator () (const unsigned char * _, size_t len)
+    {
+        length += len;
+    }
+};
+
 /* Convert a function into a sink. */
 struct LambdaSink : Sink
 {

src/nix-daemon/nix-daemon.cc

@@ -239,7 +239,15 @@ static void daemonLoop(char * * argv)
                 //  Handle the connection.
                 FdSource from(remote.get());
                 FdSink to(remote.get());
-                processConnection(openUncachedStore(), from, to, trusted, NotRecursive, user, peer.uid);
+                processConnection(openUncachedStore(), from, to, trusted, NotRecursive, [&](Store & store) {
+#if 0
+                    /* Prevent users from doing something very dangerous. */
+                    if (geteuid() == 0 &&
+                        querySetting("build-users-group", "") == "")
+                        throw Error("if you run 'nix-daemon' as root, then you MUST set 'build-users-group'!");
+#endif
+                    store.createUser(user, peer.uid);
+                });
 
                 exit(0);
             }, options);
@@ -324,7 +332,10 @@ static int _main(int argc, char * * argv)
             } else {
                 FdSource from(STDIN_FILENO);
                 FdSink to(STDOUT_FILENO);
-                processConnection(openUncachedStore(), from, to, Trusted, NotRecursive, "root", 0);
+                /* Auth hook is empty because in this mode we blindly trust the
+                   standard streams. Limitting access to thoses is explicitly
+                   not `nix-daemon`'s responsibility. */
+                processConnection(openUncachedStore(), from, to, Trusted, NotRecursive, [&](Store & _){});
             }
         } else {
             daemonLoop(argv);

src/nix-store/nix-store.cc

@@ -218,8 +218,8 @@ static StorePathSet maybeUseOutputs(const StorePath & storePath, bool useOutput,
     if (useOutput && storePath.isDerivation()) {
         auto drv = store->derivationFromPath(storePath);
         StorePathSet outputs;
-        for (auto & i : drv.outputs)
+        for (auto & i : drv.outputsAndPaths(*store))
-            outputs.insert(i.second.path(*store, drv.name));
+            outputs.insert(i.second.second);
         return outputs;
     }
     else return {storePath};
@@ -312,8 +312,8 @@ static void opQuery(Strings opFlags, Strings opArgs)
                 auto i2 = store->followLinksToStorePath(i);
                 if (forceRealise) realisePath({i2});
                 Derivation drv = store->derivationFromPath(i2);
-                for (auto & j : drv.outputs)
+                for (auto & j : drv.outputsAndPaths(*store))
-                    cout << fmt("%1%\n", store->printStorePath(j.second.path(*store, drv.name)));
+                    cout << fmt("%1%\n", store->printStorePath(j.second.second));
             }
             break;
         }
@@ -372,8 +372,8 @@ static void opQuery(Strings opFlags, Strings opArgs)
                 for (auto & j : maybeUseOutputs(store->followLinksToStorePath(i), useOutput, forceRealise)) {
                     auto info = store->queryPathInfo(j);
                     if (query == qHash) {
-                        assert(info->narHash && info->narHash->type == htSHA256);
+                        assert(info->narHash.type == htSHA256);
-                        cout << fmt("%s\n", info->narHash->to_string(Base32, true));
+                        cout << fmt("%s\n", info->narHash.to_string(Base32, true));
                     } else if (query == qSize)
                         cout << fmt("%d\n", info->narSize);
                 }
@@ -495,7 +495,10 @@ static void registerValidity(bool reregister, bool hashGiven, bool canonicalise)
     ValidPathInfos infos;
 
     while (1) {
-        auto info = decodeValidPathInfo(*store, cin, hashGiven);
+        // We use a dummy value because we'll set it below. FIXME be correct by
+        // construction and avoid dummy value.
+        auto hashResultOpt = !hashGiven ? std::optional<HashResult> { {Hash::dummy, -1} } : std::nullopt;
+        auto info = decodeValidPathInfo(*store, cin, hashResultOpt);
         if (!info) break;
         if (!store->isValidPath(info->path) || reregister) {
             /* !!! races */
@@ -723,7 +726,7 @@ static void opVerifyPath(Strings opFlags, Strings opArgs)
         auto path = store->followLinksToStorePath(i);
         printMsg(lvlTalkative, "checking path '%s'...", store->printStorePath(path));
         auto info = store->queryPathInfo(path);
-        HashSink sink(info->narHash->type);
+        HashSink sink(info->narHash.type);
         store->narFromPath(path, sink);
         auto current = sink.finish();
         if (current.first != info->narHash) {
@@ -732,7 +735,7 @@ static void opVerifyPath(Strings opFlags, Strings opArgs)
                 .hint = hintfmt(
                     "path '%s' was modified! expected hash '%s', got '%s'",
                     store->printStorePath(path),
-                    info->narHash->to_string(Base32, true),
+                    info->narHash.to_string(Base32, true),
                     current.first.to_string(Base32, true))
             });
             status = 1;
@@ -862,7 +865,7 @@ static void opServe(Strings opFlags, Strings opArgs)
                         out << info->narSize // downloadSize
                             << info->narSize;
                         if (GET_PROTOCOL_MINOR(clientVersion) >= 4)
-                            out << (info->narHash ? info->narHash->to_string(Base32, true) : "")
+                            out << info->narHash.to_string(Base32, true)
                                 << renderContentAddress(info->ca)
                                 << info->sigs;
                     } catch (InvalidPath &) {
@@ -944,11 +947,13 @@ static void opServe(Strings opFlags, Strings opArgs)
                 if (!writeAllowed) throw Error("importing paths is not allowed");
 
                 auto path = readString(in);
-                ValidPathInfo info(store->parseStorePath(path));
                 auto deriver = readString(in);
+                ValidPathInfo info {
+                    store->parseStorePath(path),
+                    Hash::parseAny(readString(in), htSHA256),
+                };
                 if (deriver != "")
                     info.deriver = store->parseStorePath(deriver);
-                info.narHash = Hash::parseAny(readString(in), htSHA256);
                 info.references = WorkerProto<StorePathSet>::read(*store, in);
                 in >> info.registrationTime >> info.narSize >> info.ultimate;
                 info.sigs = readStrings<StringSet>(in);

src/nix/add-to-store.cc

@@ -60,8 +60,10 @@ struct CmdAddToStore : MixDryRun, StoreCommand
             hash = hsink.finish().first;
         }
 
-        ValidPathInfo info(store->makeFixedOutputPath(ingestionMethod, hash, *namePart));
+        ValidPathInfo info {
-        info.narHash = narHash;
+            store->makeFixedOutputPath(ingestionMethod, hash, *namePart),
+            narHash,
+        };
         info.narSize = sink.s->size();
         info.ca = std::optional { FixedOutputHash {
             .method = ingestionMethod,

src/nix/develop.cc

@@ -124,10 +124,7 @@ StorePath getDerivationEnvironment(ref<Store> store, const StorePath & drvPath)
 
     /* Rehash and write the derivation. FIXME: would be nice to use
        'buildDerivation', but that's privileged. */
-    auto drvName = std::string(drvPath.name());
+    drv.name += "-env";
-    assert(hasSuffix(drvName, ".drv"));
-    drvName.resize(drvName.size() - 4);
-    drvName += "-env";
     for (auto & output : drv.outputs)
         drv.env.erase(output.first);
     drv.outputs = {{"out", DerivationOutput { .output = DerivationOutputInputAddressed { .path = StorePath::dummy }}}};
@@ -136,12 +133,12 @@ StorePath getDerivationEnvironment(ref<Store> store, const StorePath & drvPath)
     drv.env["outputs"] = "out";
     drv.inputSrcs.insert(std::move(getEnvShPath));
     Hash h = std::get<0>(hashDerivationModulo(*store, drv, true));
-    auto shellOutPath = store->makeOutputPath("out", h, drvName);
+    auto shellOutPath = store->makeOutputPath("out", h, drv.name);
     drv.outputs.insert_or_assign("out", DerivationOutput { .output = DerivationOutputInputAddressed {
                 .path = shellOutPath
             } });
     drv.env["out"] = store->printStorePath(shellOutPath);
-    auto shellDrvPath2 = writeDerivation(store, drv, drvName);
+    auto shellDrvPath2 = writeDerivation(store, drv);
 
     /* Build the derivation. */
     store->buildPaths({{shellDrvPath2}});

src/nix/installables.cc

@@ -304,8 +304,8 @@ struct InstallableStorePath : Installable
         if (storePath.isDerivation()) {
             std::map<std::string, StorePath> outputs;
             auto drv = store->readDerivation(storePath);
-            for (auto & [name, output] : drv.outputs)
+            for (auto & i : drv.outputsAndPaths(*store))
-                outputs.emplace(name, output.path(*store, drv.name));
+                outputs.emplace(i.first, i.second.second);
             return {
                 BuildableFromDrv {
                     .drvPath = storePath,

src/nix/make-content-addressable.cc

@@ -77,14 +77,16 @@ struct CmdMakeContentAddressable : StorePathsCommand, MixJSON
 
             auto narHash = hashModuloSink.finish().first;
 
-            ValidPathInfo info(store->makeFixedOutputPath(FileIngestionMethod::Recursive, narHash, path.name(), references, hasSelfReference));
+            ValidPathInfo info {
+                store->makeFixedOutputPath(FileIngestionMethod::Recursive, narHash, path.name(), references, hasSelfReference),
+                narHash,
+            };
             info.references = std::move(references);
             if (hasSelfReference) info.references.insert(info.path);
-            info.narHash = narHash;
             info.narSize = sink.s->size();
             info.ca = FixedOutputHash {
                 .method = FileIngestionMethod::Recursive,
-                .hash = *info.narHash,
+                .hash = info.narHash,
             };
 
             if (!json)

src/nix/profile.cc

@@ -129,11 +129,13 @@ struct ProfileManifest
 
         auto narHash = hashString(htSHA256, *sink.s);
 
-        ValidPathInfo info(store->makeFixedOutputPath(FileIngestionMethod::Recursive, narHash, "profile", references));
+        ValidPathInfo info {
+            store->makeFixedOutputPath(FileIngestionMethod::Recursive, narHash, "profile", references),
+            narHash,
+        };
         info.references = std::move(references);
-        info.narHash = narHash;
         info.narSize = sink.s->size();
-        info.ca = FixedOutputHash { .method = FileIngestionMethod::Recursive, .hash = *info.narHash };
+        info.ca = FixedOutputHash { .method = FileIngestionMethod::Recursive, .hash = info.narHash };
 
         auto source = StringSource { *sink.s };
         store->addToStore(info, source);

src/nix/repl.cc

@@ -490,8 +490,8 @@ bool NixRepl::processLine(string line)
             if (runProgram(settings.nixBinDir + "/nix", Strings{"build", "--no-link", drvPath}) == 0) {
                 auto drv = readDerivation(*state->store, drvPath, Derivation::nameFromPath(state->store->parseStorePath(drvPath)));
                 std::cout << std::endl << "this derivation produced the following outputs:" << std::endl;
-                for (auto & i : drv.outputs)
+                for (auto & i : drv.outputsAndPaths(*state->store))
-                    std::cout << fmt("  %s -> %s\n", i.first, state->store->printStorePath(i.second.path(*state->store, drv.name)));
+                    std::cout << fmt("  %s -> %s\n", i.first, state->store->printStorePath(i.second.second));
             }
         } else if (command == ":i") {
             runProgram(settings.nixBinDir + "/nix-env", Strings{"-i", drvPath});

src/nix/show-derivation.cc

@@ -67,9 +67,9 @@ struct CmdShowDerivation : InstallablesCommand
 
             {
                 auto outputsObj(drvObj.object("outputs"));
-                for (auto & output : drv.outputs) {
+                for (auto & output : drv.outputsAndPaths(*store)) {
                     auto outputObj(outputsObj.object(output.first));
-                    outputObj.attr("path", store->printStorePath(output.second.path(*store, drv.name)));
+                    outputObj.attr("path", store->printStorePath(output.second.second));
 
                     std::visit(overloaded {
                         [&](DerivationOutputInputAddressed doi) {
@@ -81,7 +81,7 @@ struct CmdShowDerivation : InstallablesCommand
                         [&](DerivationOutputCAFloating dof) {
                             outputObj.attr("hashAlgo", makeFileIngestionPrefix(dof.method) + printHashType(dof.hashType));
                         },
-                    }, output.second.output);
+                    }, output.second.first.output);
                 }
             }
 

src/nix/verify.cc

@@ -91,15 +91,15 @@ struct CmdVerify : StorePathsCommand
 
                     std::unique_ptr<AbstractHashSink> hashSink;
                     if (!info->ca)
-                        hashSink = std::make_unique<HashSink>(info->narHash->type);
+                        hashSink = std::make_unique<HashSink>(info->narHash.type);
                     else
-                        hashSink = std::make_unique<HashModuloSink>(info->narHash->type, std::string(info->path.hashPart()));
+                        hashSink = std::make_unique<HashModuloSink>(info->narHash.type, std::string(info->path.hashPart()));
 
                     store->narFromPath(info->path, *hashSink);
 
                     auto hash = hashSink->finish();
 
-                    if (hash.first != *info->narHash) {
+                    if (hash.first != info->narHash) {
                         corrupted++;
                         act2.result(resCorruptedPath, store->printStorePath(info->path));
                         logError({
@@ -107,7 +107,7 @@ struct CmdVerify : StorePathsCommand
                             .hint = hintfmt(
                                 "path '%s' was modified! expected hash '%s', got '%s'",
                                 store->printStorePath(info->path),
-                                info->narHash->to_string(Base32, true),
+                                info->narHash.to_string(Base32, true),
                                 hash.first.to_string(Base32, true))
                         });
                     }

tests/binary-cache.sh

@@ -219,7 +219,7 @@ outPath=$(nix-build --no-out-link -E '
 nix copy --to file://$cacheDir?write-nar-listing=1 $outPath
 
 diff -u \
-    <(jq -S < $cacheDir/$(basename $outPath).ls) \
+    <(jq -S < $cacheDir/$(basename $outPath | cut -c1-32).ls) \
     <(echo '{"version":1,"root":{"type":"directory","entries":{"bar":{"type":"regular","size":4,"narOffset":232},"link":{"type":"symlink","target":"xyzzy"}}}}' | jq -S)
 
 

tests/build-hook-ca.nix

@@ -0,0 +1,45 @@
+{ busybox }:
+
+with import ./config.nix;
+
+let
+
+  mkDerivation = args:
+    derivation ({
+      inherit system;
+      builder = busybox;
+      args = ["sh" "-e" args.builder or (builtins.toFile "builder-${args.name}.sh" "if [ -e .attrs.sh ]; then source .attrs.sh; fi; eval \"$buildCommand\"")];
+      outputHashMode = "recursive";
+      outputHashAlgo = "sha256";
+    } // removeAttrs args ["builder" "meta"])
+    // { meta = args.meta or {}; };
+
+  input1 = mkDerivation {
+    shell = busybox;
+    name = "build-remote-input-1";
+    buildCommand = "echo FOO > $out";
+    requiredSystemFeatures = ["foo"];
+    outputHash = "sha256-FePFYIlMuycIXPZbWi7LGEiMmZSX9FMbaQenWBzm1Sc=";
+  };
+
+  input2 = mkDerivation {
+    shell = busybox;
+    name = "build-remote-input-2";
+    buildCommand = "echo BAR > $out";
+    requiredSystemFeatures = ["bar"];
+    outputHash = "sha256-XArauVH91AVwP9hBBQNlkX9ccuPpSYx9o0zeIHb6e+Q=";
+  };
+
+in
+
+  mkDerivation {
+    shell = busybox;
+    name = "build-remote";
+    buildCommand =
+      ''
+        read x < ${input1}
+        read y < ${input2}
+        echo "$x $y" > $out
+      '';
+    outputHash = "sha256-3YGhlOfbGUm9hiPn2teXXTT8M1NEpDFvfXkxMaJRld0=";
+  }

tests/build-hook.nix

@@ -23,6 +23,17 @@ let
     shell = busybox;
     name = "build-remote-input-2";
     buildCommand = "echo BAR > $out";
+    requiredSystemFeatures = ["bar"];
+  };
+
+  input3 = mkDerivation {
+    shell = busybox;
+    name = "build-remote-input-3";
+    buildCommand = ''
+      read x < ${input2}
+      echo $x BAZ > $out
+    '';
+    requiredSystemFeatures = ["baz"];
   };
 
 in
@@ -33,7 +44,7 @@ in
     buildCommand =
       ''
         read x < ${input1}
-        read y < ${input2}
+        read y < ${input3}
-        echo $x$y > $out
+        echo "$x $y" > $out
       '';
   }

tests/build-remote-content-addressed-fixed.sh

@@ -0,0 +1,5 @@
+source common.sh
+
+file=build-hook-ca.nix
+
+source build-remote.sh

tests/build-remote-input-addressed.sh

@@ -0,0 +1,5 @@
+source common.sh
+
+file=build-hook.nix
+
+source build-remote.sh

tests/build-remote.sh

@@ -1,31 +1,47 @@
-source common.sh
-
-clearStore
-
 if ! canUseSandbox; then exit; fi
 if ! [[ $busybox =~ busybox ]]; then exit; fi
 
-chmod -R u+w $TEST_ROOT/machine0 || true
-chmod -R u+w $TEST_ROOT/machine1 || true
-chmod -R u+w $TEST_ROOT/machine2 || true
-rm -rf $TEST_ROOT/machine0 $TEST_ROOT/machine1 $TEST_ROOT/machine2
-rm -f $TEST_ROOT/result
-
 unset NIX_STORE_DIR
 unset NIX_STATE_DIR
 
+function join_by { local d=$1; shift; echo -n "$1"; shift; printf "%s" "${@/#/$d}"; }
+
+builders=(
+  # system-features will automatically be added to the outer URL, but not inner
+  # remote-store URL.
+  "ssh://localhost?remote-store=$TEST_ROOT/machine1?system-features=foo - - 1 1 foo"
+  "$TEST_ROOT/machine2 - - 1 1 bar"
+  "ssh-ng://localhost?remote-store=$TEST_ROOT/machine3?system-features=baz - - 1 1 baz"
+)
+
 # Note: ssh://localhost bypasses ssh, directly invoking nix-store as a
 # child process. This allows us to test LegacySSHStore::buildDerivation().
-nix build -L -v -f build-hook.nix -o $TEST_ROOT/result --max-jobs 0 \
+# ssh-ng://... likewise allows us to test RemoteStore::buildDerivation().
+nix build -L -v -f $file -o $TEST_ROOT/result --max-jobs 0 \
   --arg busybox $busybox \
   --store $TEST_ROOT/machine0 \
-  --builders "ssh://localhost?remote-store=$TEST_ROOT/machine1; $TEST_ROOT/machine2 - - 1 1 foo" \
+  --builders "$(join_by '; ' "${builders[@]}")"
-  --system-features foo
 
 outPath=$(readlink -f $TEST_ROOT/result)
 
-cat $TEST_ROOT/machine0/$outPath | grep FOOBAR
+grep 'FOO BAR BAZ' $TEST_ROOT/machine0/$outPath
 
-# Ensure that input1 was built on store2 due to the required feature.
+set -o pipefail
-(! nix path-info --store $TEST_ROOT/machine1 --all | grep builder-build-remote-input-1.sh)
+
-nix path-info --store $TEST_ROOT/machine2 --all | grep builder-build-remote-input-1.sh
+# Ensure that input1 was built on store1 due to the required feature.
+nix path-info --store $TEST_ROOT/machine1 --all \
+  | grep builder-build-remote-input-1.sh \
+  | grep -v builder-build-remote-input-2.sh \
+  | grep -v builder-build-remote-input-3.sh
+
+# Ensure that input2 was built on store2 due to the required feature.
+nix path-info --store $TEST_ROOT/machine2 --all \
+  | grep -v builder-build-remote-input-1.sh \
+  | grep builder-build-remote-input-2.sh \
+  | grep -v builder-build-remote-input-3.sh
+
+# Ensure that input3 was built on store3 due to the required feature.
+nix path-info --store $TEST_ROOT/machine3 --all \
+  | grep -v builder-build-remote-input-1.sh \
+  | grep -v builder-build-remote-input-2.sh \
+  | grep builder-build-remote-input-3.sh

tests/local.mk

@@ -1,5 +1,5 @@
 nix_tests = \
-  init.sh hash.sh lang.sh add.sh simple.sh dependencies.sh \
+  hash.sh lang.sh add.sh simple.sh dependencies.sh \
   config.sh \
   gc.sh \
   gc-concurrent.sh \
@@ -14,7 +14,7 @@ nix_tests = \
   placeholders.sh nix-shell.sh \
   linux-sandbox.sh \
   build-dry.sh \
-  build-remote.sh \
+  build-remote-input-addressed.sh \
   nar-access.sh \
   structured-attrs.sh \
   fetchGit.sh \
@@ -34,6 +34,7 @@ nix_tests = \
   recursive.sh \
   flakes.sh
   # parallel.sh
+  # build-remote-content-addressed-fixed.sh \
 
 install-tests += $(foreach x, $(nix_tests), tests/$(x))
 

tests/remote-store.sh

@@ -2,6 +2,9 @@ source common.sh
 
 clearStore
 
+# Ensure "fake ssh" remote store works just as legacy fake ssh would.
+nix --store ssh-ng://localhost?remote-store=$TEST_ROOT/other-store doctor
+
 startDaemon
 
 storeCleared=1 NIX_REMOTE_=$NIX_REMOTE $SHELL ./user-envs.sh