treewide: consistently mark overridden settings as such

Only overridden settings are sent to the daemon, and we're going to do the same
for the build hook to. It needs to be ensured that overridden settings are in
fact consistently marked as such, so that they actually get sent.

Change-Id: I7cd58d925702f86cf2c35ad121eb191ceb62a355

src/legacy/nix-store.cc

@@ -831,12 +831,12 @@ static void opServe(Strings opFlags, Strings opArgs)
         // FIXME: changing options here doesn't work if we're
         // building through the daemon.
         verbosity = lvlError;
-        settings.keepLog = false;
+        settings.keepLog.override(false);
-        settings.useSubstitutes = false;
+        settings.useSubstitutes.override(false);
-        settings.maxSilentTime = readInt(in);
+        settings.maxSilentTime.override(readInt(in));
-        settings.buildTimeout = readInt(in);
+        settings.buildTimeout.override(readInt(in));
         if (GET_PROTOCOL_MINOR(clientVersion) >= 2)
-            settings.maxLogSize = readNum<unsigned long>(in);
+            settings.maxLogSize.override(readNum<unsigned long>(in));
         if (GET_PROTOCOL_MINOR(clientVersion) >= 3) {
             auto nrRepeats = readInt(in);
             if (nrRepeats != 0) {
@@ -850,10 +850,10 @@ static void opServe(Strings opFlags, Strings opArgs)
             // asked for.
             readInt(in);
 
-            settings.runDiffHook = true;
+            settings.runDiffHook.override(true);
         }
         if (GET_PROTOCOL_MINOR(clientVersion) >= 7) {
-            settings.keepFailed = (bool) readInt(in);
+            settings.keepFailed.override((bool) readInt(in));
         }
     };
 

src/libcmd/common-eval-args.cc

@@ -137,7 +137,7 @@ MixEvalArgs::MixEvalArgs()
         .description = "Allow access to mutable paths and repositories.",
         .category = category,
         .handler = {[&]() {
-            evalSettings.pureEval = false;
+            evalSettings.pureEval.override(false);
         }},
     });
 

src/libcmd/installables.cc

@@ -212,7 +212,7 @@ void SourceExprCommand::completeInstallable(AddCompletions & completions, std::s
         if (file) {
             completions.setType(AddCompletions::Type::Attrs);
 
-            evalSettings.pureEval = false;
+            evalSettings.pureEval.override(false);
             auto state = getEvalState();
             Expr & e = state->parseExprFromFile(
                 resolveExprPath(state->checkSourcePath(lookupFileArg(*state, *file)))
@@ -435,7 +435,7 @@ Installables SourceExprCommand::parseInstallables(
             throw UsageError("'--file' and '--expr' are exclusive");
 
         // FIXME: backward compatibility hack
-        if (file) evalSettings.pureEval = false;
+        if (file) evalSettings.pureEval.override(false);
 
         auto state = getEvalState();
         auto vFile = state->allocValue();

src/libcmd/repl.cc

@@ -817,10 +817,10 @@ ProcessLineResult NixRepl::processLine(std::string line)
     else if (command == ":te" || command == ":trace-enable") {
         if (arg == "false" || (arg == "" && loggerSettings.showTrace)) {
             std::cout << "not showing error traces\n";
-            loggerSettings.showTrace = false;
+            loggerSettings.showTrace.override(false);
         } else if (arg == "true" || (arg == "" && !loggerSettings.showTrace)) {
             std::cout << "showing error traces\n";
-            loggerSettings.showTrace = true;
+            loggerSettings.showTrace.override(true);
         } else {
             throw Error("unexpected argument '%s' to %s", arg, command);
         };

src/libexpr/eval-settings.cc

@@ -47,7 +47,7 @@ static Strings parseNixPath(const std::string & s)
 EvalSettings::EvalSettings()
 {
     auto var = getEnv("NIX_PATH");
-    if (var) nixPath = parseNixPath(*var);
+    if (var) nixPath.setDefault(parseNixPath(*var));
 }
 
 Strings EvalSettings::getDefaultNixPath()

src/libmain/shared.cc

@@ -196,20 +196,20 @@ LegacyArgs::LegacyArgs(const std::string & programName,
         .longName = "keep-failed",
         .shortName ='K',
         .description = "Keep temporary directories of failed builds.",
-        .handler = {&(bool&) settings.keepFailed, true},
+        .handler = {[&]() { settings.keepFailed.override(true); }},
     });
 
     addFlag({
         .longName = "keep-going",
         .shortName ='k',
         .description = "Keep going after a build fails.",
-        .handler = {&(bool&) settings.keepGoing, true},
+        .handler = {[&]() { settings.keepGoing.override(true); }},
     });
 
     addFlag({
         .longName = "fallback",
         .description = "Build from source if substitution fails.",
-        .handler = {&(bool&) settings.tryFallback, true},
+        .handler = {[&]() { settings.tryFallback.override(true); }},
     });
 
     auto intSettingAlias = [&](char shortName, const std::string & longName,
@@ -247,7 +247,7 @@ LegacyArgs::LegacyArgs(const std::string & programName,
         .longName = "store",
         .description = "The URL of the Nix store to use.",
         .labels = {"store-uri"},
-        .handler = {&(std::string&) settings.storeUri},
+        .handler = {[&](std::string storeUri) { settings.storeUri.override(storeUri); }},
     });
 }
 

src/libstore/builtins/fetchurl.cc

@@ -13,11 +13,11 @@ void builtinFetchurl(const BasicDerivation & drv, const std::string & netrcData,
        this to be stored in a file. It would be nice if we could just
        pass a pointer to the data. */
     if (netrcData != "") {
-        settings.netrcFile = "netrc";
+        settings.netrcFile.override("netrc");
         writeFile(settings.netrcFile, netrcData, 0600);
     }
 
-    settings.caFile = "ca-certificates.crt";
+    settings.caFile.override("ca-certificates.crt");
     writeFile(settings.caFile, caFileData, 0600);
 
     auto getAttr = [&](const std::string & name) {

src/libstore/daemon.cc

@@ -195,15 +195,15 @@ struct ClientSettings
 
     void apply(TrustedFlag trusted)
     {
-        settings.keepFailed = keepFailed;
+        settings.keepFailed.override(keepFailed);
-        settings.keepGoing = keepGoing;
+        settings.keepGoing.override(keepGoing);
-        settings.tryFallback = tryFallback;
+        settings.tryFallback.override(tryFallback);
         nix::verbosity = verbosity;
-        settings.maxBuildJobs.assign(maxBuildJobs);
+        settings.maxBuildJobs.override(maxBuildJobs);
-        settings.maxSilentTime = maxSilentTime;
+        settings.maxSilentTime.override(maxSilentTime);
         settings.verboseBuild = verboseBuild;
-        settings.buildCores = buildCores;
+        settings.buildCores.override(buildCores);
-        settings.useSubstitutes = useSubstitutes;
+        settings.useSubstitutes.override(useSubstitutes);
 
         for (auto & i : overrides) {
             auto & name(i.first);
@@ -225,12 +225,13 @@ struct ClientSettings
                     else
                         warn("ignoring untrusted substituter '%s', you are not a trusted user.\n"
                              "Run `man nix.conf` for more information on the `substituters` configuration option.", s);
-                res = subs;
+                res.override(subs);
                 return true;
             };
 
             try {
-                if (name == "ssh-auth-sock") // obsolete
+                if (name == "ssh-auth-sock" // obsolete
+                    || name == "store") // the daemon *is* the store
                     ;
                 else if (name == experimentalFeatureSettings.experimentalFeatures.name) {
                     // We don’t want to forward the experimental features to

src/libstore/globals.cc

@@ -69,12 +69,12 @@ Settings::Settings()
     , nixManDir(canonPath(NIX_MAN_DIR))
     , nixDaemonSocketFile(canonPath(getEnvNonEmpty("NIX_DAEMON_SOCKET_PATH").value_or(nixStateDir + DEFAULT_SOCKET_PATH)))
 {
-    buildUsersGroup = getuid() == 0 ? "nixbld" : "";
+    buildUsersGroup.setDefault(getuid() == 0 ? "nixbld" : "");
-    allowSymlinkedStore = getEnv("NIX_IGNORE_SYMLINK_STORE") == "1";
+    allowSymlinkedStore.setDefault(getEnv("NIX_IGNORE_SYMLINK_STORE") == "1");
 
     auto sslOverride = getEnv("NIX_SSL_CERT_FILE").value_or(getEnv("SSL_CERT_FILE").value_or(""));
     if (sslOverride != "")
-        caFile = sslOverride;
+        caFile.setDefault(sslOverride);
 
     /* Backwards compatibility. */
     auto s = getEnv("NIX_REMOTE_SYSTEMS");
@@ -82,17 +82,17 @@ Settings::Settings()
         Strings ss;
         for (auto & p : tokenizeString<Strings>(*s, ":"))
             ss.push_back("@" + p);
-        builders = concatStringsSep(" ", ss);
+        builders.setDefault(concatStringsSep(" ", ss));
     }
 
 #if defined(__linux__) && defined(SANDBOX_SHELL)
-    sandboxPaths = tokenizeString<StringSet>("/bin/sh=" SANDBOX_SHELL);
+    sandboxPaths.setDefault(tokenizeString<StringSet>("/bin/sh=" SANDBOX_SHELL));
 #endif
 
     /* chroot-like behavior from Apple's sandbox */
 #if __APPLE__
-    sandboxPaths = tokenizeString<StringSet>("/System/Library/Frameworks /System/Library/PrivateFrameworks /bin/sh /bin/bash /private/tmp /private/var/tmp /usr/lib");
+    sandboxPaths.setDefault(tokenizeString<StringSet>("/System/Library/Frameworks /System/Library/PrivateFrameworks /bin/sh /bin/bash /private/tmp /private/var/tmp /usr/lib"));
-    allowedImpureHostPrefixes = tokenizeString<StringSet>("/System/Library /usr/lib /dev /bin/sh");
+    allowedImpureHostPrefixes.setDefault(tokenizeString<StringSet>("/System/Library /usr/lib /dev /bin/sh"));
 #endif
 
     /* Set the build hook location
@@ -118,10 +118,10 @@ Settings::Settings()
     if (!pathExists(nixExePath)) {
         nixExePath = getSelfExe().value_or("nix");
     }
-    buildHook = {
+    buildHook.setDefault(Strings {
         nixExePath,
         "__build-remote",
-    };
+    });
 }
 
 void loadConfFile()

src/libstore/remote-store.cc

@@ -139,6 +139,7 @@ void RemoteStore::setOptions(Connection & conn)
     overrides.erase(loggerSettings.showTrace.name);
     overrides.erase(experimentalFeatureSettings.experimentalFeatures.name);
     overrides.erase(settings.pluginFiles.name);
+    overrides.erase(settings.storeUri.name); // the daemon *is* the store
     conn.to << overrides.size();
     for (auto & i : overrides)
         conn.to << i.first << i.second.value;

src/libutil/config-impl.hh

@@ -65,6 +65,7 @@ void BaseSetting<T>::appendOrSet(T newValue, bool append, const ApplyConfigOptio
         "using default `appendOrSet` implementation with an appendable type");
     assert(!append);
 
+    overridden = true;
     value = std::move(newValue);
 }
 
@@ -85,6 +86,13 @@ void BaseSetting<T>::set(const std::string & str, bool append, const ApplyConfig
     }
 }
 
+template<typename T>
+void BaseSetting<T>::override(const T & v)
+{
+    overridden = true;
+    value = v;
+}
+
 template<> void BaseSetting<bool>::convertToArg(Args & args, const std::string & category);
 
 template<typename T>
@@ -95,7 +103,7 @@ void BaseSetting<T>::convertToArg(Args & args, const std::string & category)
         .description = fmt("Set the `%s` setting.", name),
         .category = category,
         .labels = {"value"},
-        .handler = {[this](std::string s) { overridden = true; set(s); }},
+        .handler = {[this](std::string s) { set(s); }},
         .experimentalFeature = experimentalFeature,
     });
 
@@ -105,7 +113,7 @@ void BaseSetting<T>::convertToArg(Args & args, const std::string & category)
             .description = fmt("Append to the `%s` setting.", name),
             .category = category,
             .labels = {"value"},
-            .handler = {[this](std::string s) { overridden = true; set(s, true); }},
+            .handler = {[this](std::string s) { set(s, true); }},
             .experimentalFeature = experimentalFeature,
         });
 }

src/libutil/config.cc

@@ -32,7 +32,6 @@ bool Config::set(const std::string & name, const std::string & value, const Appl
             return false;
     }
     i->second.setting->set(value, append, options);
-    i->second.setting->overridden = true;
     return true;
 }
 
@@ -46,7 +45,6 @@ void Config::addSetting(AbstractSetting * setting)
 
     if (auto i = unknownSettings.find(setting->name); i != unknownSettings.end()) {
         setting->set(std::move(i->second));
-        setting->overridden = true;
         unknownSettings.erase(i);
         set = true;
     }
@@ -58,7 +56,6 @@ void Config::addSetting(AbstractSetting * setting)
                     alias, setting->name);
             else {
                 setting->set(std::move(i->second));
-                setting->overridden = true;
                 unknownSettings.erase(i);
                 set = true;
             }

src/libutil/config.hh

@@ -218,6 +218,7 @@ protected:
     virtual void convertToArg(Args & args, const std::string & category);
 
     bool isOverridden() const;
+
 };
 
 /**
@@ -267,16 +268,12 @@ public:
     { }
 
     operator const T &() const { return value; }
-    operator T &() { return value; }
     const T & get() const { return value; }
     template<typename U>
     bool operator ==(const U & v2) const { return value == v2; }
     template<typename U>
     bool operator !=(const U & v2) const { return value != v2; }
     template<typename U>
-    void operator =(const U & v) { assign(v); }
-    virtual void assign(const T & v) { value = v; }
-    template<typename U>
     void setDefault(const U & v) { if (!overridden) value = v; }
 
     /**
@@ -287,6 +284,8 @@ public:
      */
     void set(const std::string & str, bool append = false, const ApplyConfigOptions & options = {}) override final;
 
+    void override(const T & v);
+
     /**
      * C++ trick; This is template-specialized to compile-time indicate whether
      * the type is appendable.
@@ -299,12 +298,6 @@ public:
      */
     bool isAppendable() override final;
 
-    virtual void override(const T & v)
-    {
-        overridden = true;
-        value = v;
-    }
-
     std::string to_string() const override;
 
     void convertToArg(Args & args, const std::string & category) override;
@@ -349,8 +342,6 @@ public:
         : Setting(options, def, name, description, aliases, documentDefault, std::move(experimentalFeature), true)
     {
     }
-
-    void operator =(const T & v) { this->assign(v); }
 };
 
 /**
@@ -375,8 +366,6 @@ public:
     }
 
     T parse(const std::string & str, const ApplyConfigOptions & options) const override;
-
-    void operator =(const T & v) { this->assign(v); }
 };
 
 

src/nix/flake.cc

@@ -116,7 +116,7 @@ public:
 
     void run(nix::ref<nix::Store> store) override
     {
-        settings.tarballTtl = 0;
+        settings.tarballTtl.override(0);
         auto updateAll = lockFlags.inputUpdates.empty();
 
         lockFlags.recreateLockFile = updateAll;
@@ -158,7 +158,7 @@ struct CmdFlakeLock : FlakeCommand
 
     void run(nix::ref<nix::Store> store) override
     {
-        settings.tarballTtl = 0;
+        settings.tarballTtl.override(0);
 
         lockFlags.writeLockFile = true;
         lockFlags.applyNixConfig = true;

src/nix/main.cc

@@ -247,8 +247,8 @@ static void showHelp(std::vector<std::string> subcommand, NixArgs & toplevel)
 {
     auto mdName = subcommand.empty() ? "nix" : fmt("nix3-%s", concatStringsSep("-", subcommand));
 
-    evalSettings.restrictEval = false;
+    evalSettings.restrictEval.override(false);
-    evalSettings.pureEval = false;
+    evalSettings.pureEval.override(false);
     EvalState state({}, openStore("dummy://"));
 
     auto vGenerateManpage = state.allocValue();
@@ -389,7 +389,7 @@ void mainWrapped(int argc, char * * argv)
         if (legacy) return legacy(argc, argv);
     }
 
-    evalSettings.pureEval = true;
+    evalSettings.pureEval.setDefault(true);
 
     setLogFormat(LogFormat::bar);
     settings.verboseBuild = false;
@@ -408,11 +408,11 @@ void mainWrapped(int argc, char * * argv)
     }
 
     if (argc == 2 && std::string(argv[1]) == "__dump-language") {
-        experimentalFeatureSettings.experimentalFeatures = ExperimentalFeatures{}
+        experimentalFeatureSettings.experimentalFeatures.override(ExperimentalFeatures{}
             | Xp::Flakes
             | Xp::FetchClosure
-            | Xp::DynamicDerivations;
+            | Xp::DynamicDerivations);
-        evalSettings.pureEval = false;
+        evalSettings.pureEval.override(false);
         EvalState state({}, openStore("dummy://"));
         auto res = nlohmann::json::object();
         res["builtins"] = ({
@@ -513,24 +513,20 @@ void mainWrapped(int argc, char * * argv)
 
     if (!args.useNet) {
         // FIXME: should check for command line overrides only.
-        if (!settings.useSubstitutes.overridden)
+        settings.useSubstitutes.setDefault(false);
-            settings.useSubstitutes = false;
+        settings.tarballTtl.setDefault(std::numeric_limits<unsigned int>::max());
-        if (!settings.tarballTtl.overridden)
+        fileTransferSettings.tries.setDefault(0);
-            settings.tarballTtl = std::numeric_limits<unsigned int>::max();
+        fileTransferSettings.connectTimeout.setDefault(1);
-        if (!fileTransferSettings.tries.overridden)
-            fileTransferSettings.tries = 0;
-        if (!fileTransferSettings.connectTimeout.overridden)
-            fileTransferSettings.connectTimeout = 1;
     }
 
     if (args.refresh) {
-        settings.tarballTtl = 0;
+        settings.tarballTtl.override(0);
-        settings.ttlNegativeNarInfoCache = 0;
+        settings.ttlNegativeNarInfoCache.override(0);
-        settings.ttlPositiveNarInfoCache = 0;
+        settings.ttlPositiveNarInfoCache.override(0);
     }
 
-    if (args.command->second->forceImpureByDefault() && !evalSettings.pureEval.overridden) {
+    if (args.command->second->forceImpureByDefault()) {
-        evalSettings.pureEval = false;
+        evalSettings.pureEval.setDefault(false);
     }
     args.command->second->run();
 }

src/nix/repl.cc

@@ -10,7 +10,7 @@ namespace nix {
 struct CmdRepl : RawInstallablesCommand
 {
     CmdRepl() {
-        evalSettings.pureEval = false;
+        evalSettings.pureEval.override(false);
     }
 
     /**

src/nix/upgrade-nix.cc

@@ -72,7 +72,7 @@ struct CmdUpgradeNix : MixDryRun, EvalCommand
 
     void run(ref<Store> store) override
     {
-        evalSettings.pureEval = true;
+        evalSettings.pureEval.override(true);
 
         if (profileDir == "") {
             profileDir = getProfileDir(store);

tests/unit/libstore/machines.cc

@@ -24,20 +24,20 @@ using nix::settings;
 
 class Environment : public ::testing::Environment {
   public:
-    void SetUp() override { settings.thisSystem = "TEST_ARCH-TEST_OS"; }
+    void SetUp() override { settings.thisSystem.override("TEST_ARCH-TEST_OS"); }
 };
 
 testing::Environment* const foo_env =
     testing::AddGlobalTestEnvironment(new Environment);
 
 TEST(machines, getMachinesWithEmptyBuilders) {
-    settings.builders = "";
+    settings.builders.override("");
     Machines actual = getMachines();
     ASSERT_THAT(actual, SizeIs(0));
 }
 
 TEST(machines, getMachinesUriOnly) {
-    settings.builders = "nix@scratchy.labs.cs.uu.nl";
+    settings.builders.override("nix@scratchy.labs.cs.uu.nl");
     Machines actual = getMachines();
     ASSERT_THAT(actual, SizeIs(1));
     EXPECT_THAT(actual[0], Field(&Machine::storeUri, Eq("ssh://nix@scratchy.labs.cs.uu.nl")));
@@ -51,7 +51,7 @@ TEST(machines, getMachinesUriOnly) {
 }
 
 TEST(machines, getMachinesDefaults) {
-    settings.builders = "nix@scratchy.labs.cs.uu.nl - - - - - - -";
+    settings.builders.override("nix@scratchy.labs.cs.uu.nl - - - - - - -");
     Machines actual = getMachines();
     ASSERT_THAT(actual, SizeIs(1));
     EXPECT_THAT(actual[0], Field(&Machine::storeUri, Eq("ssh://nix@scratchy.labs.cs.uu.nl")));
@@ -65,7 +65,7 @@ TEST(machines, getMachinesDefaults) {
 }
 
 TEST(machines, getMachinesWithNewLineSeparator) {
-    settings.builders = "nix@scratchy.labs.cs.uu.nl\nnix@itchy.labs.cs.uu.nl";
+    settings.builders.override("nix@scratchy.labs.cs.uu.nl\nnix@itchy.labs.cs.uu.nl");
     Machines actual = getMachines();
     ASSERT_THAT(actual, SizeIs(2));
     EXPECT_THAT(actual, Contains(Field(&Machine::storeUri, EndsWith("nix@scratchy.labs.cs.uu.nl"))));
@@ -73,7 +73,7 @@ TEST(machines, getMachinesWithNewLineSeparator) {
 }
 
 TEST(machines, getMachinesWithSemicolonSeparator) {
-    settings.builders = "nix@scratchy.labs.cs.uu.nl ; nix@itchy.labs.cs.uu.nl";
+    settings.builders.override("nix@scratchy.labs.cs.uu.nl ; nix@itchy.labs.cs.uu.nl");
     Machines actual = getMachines();
     EXPECT_THAT(actual, SizeIs(2));
     EXPECT_THAT(actual, Contains(Field(&Machine::storeUri, EndsWith("nix@scratchy.labs.cs.uu.nl"))));
@@ -81,9 +81,9 @@ TEST(machines, getMachinesWithSemicolonSeparator) {
 }
 
 TEST(machines, getMachinesWithCorrectCompleteSingleBuilder) {
-    settings.builders = "nix@scratchy.labs.cs.uu.nl     i686-linux      "
+    settings.builders.override("nix@scratchy.labs.cs.uu.nl     i686-linux      "
                         "/home/nix/.ssh/id_scratchy_auto        8 3 kvm "
-                        "benchmark SSH+HOST+PUBLIC+KEY+BASE64+ENCODED==";
+                        "benchmark SSH+HOST+PUBLIC+KEY+BASE64+ENCODED==");
     Machines actual = getMachines();
     ASSERT_THAT(actual, SizeIs(1));
     EXPECT_THAT(actual[0], Field(&Machine::storeUri, EndsWith("nix@scratchy.labs.cs.uu.nl")));
@@ -98,10 +98,10 @@ TEST(machines, getMachinesWithCorrectCompleteSingleBuilder) {
 
 TEST(machines,
      getMachinesWithCorrectCompleteSingleBuilderWithTabColumnDelimiter) {
-    settings.builders =
+    settings.builders.override(
         "nix@scratchy.labs.cs.uu.nl\ti686-linux\t/home/nix/.ssh/"
         "id_scratchy_auto\t8\t3\tkvm\tbenchmark\tSSH+HOST+PUBLIC+"
-        "KEY+BASE64+ENCODED==";
+        "KEY+BASE64+ENCODED==");
     Machines actual = getMachines();
     ASSERT_THAT(actual, SizeIs(1));
     EXPECT_THAT(actual[0], Field(&Machine::storeUri, EndsWith("nix@scratchy.labs.cs.uu.nl")));
@@ -115,9 +115,9 @@ TEST(machines,
 }
 
 TEST(machines, getMachinesWithMultiOptions) {
-    settings.builders = "nix@scratchy.labs.cs.uu.nl Arch1,Arch2 - - - "
+    settings.builders.override("nix@scratchy.labs.cs.uu.nl Arch1,Arch2 - - - "
                         "SupportedFeature1,SupportedFeature2 "
-                        "MandatoryFeature1,MandatoryFeature2";
+                        "MandatoryFeature1,MandatoryFeature2");
     Machines actual = getMachines();
     ASSERT_THAT(actual, SizeIs(1));
     EXPECT_THAT(actual[0], Field(&Machine::storeUri, EndsWith("nix@scratchy.labs.cs.uu.nl")));
@@ -127,15 +127,15 @@ TEST(machines, getMachinesWithMultiOptions) {
 }
 
 TEST(machines, getMachinesWithIncorrectFormat) {
-    settings.builders = "nix@scratchy.labs.cs.uu.nl - - eight";
+    settings.builders.override("nix@scratchy.labs.cs.uu.nl - - eight");
     EXPECT_THROW(getMachines(), FormatError);
-    settings.builders = "nix@scratchy.labs.cs.uu.nl - - -1";
+    settings.builders.override("nix@scratchy.labs.cs.uu.nl - - -1");
     EXPECT_THROW(getMachines(), FormatError);
-    settings.builders = "nix@scratchy.labs.cs.uu.nl - - 8 three";
+    settings.builders.override("nix@scratchy.labs.cs.uu.nl - - 8 three");
     EXPECT_THROW(getMachines(), FormatError);
-    settings.builders = "nix@scratchy.labs.cs.uu.nl - - 8 -3";
+    settings.builders.override("nix@scratchy.labs.cs.uu.nl - - 8 -3");
     EXPECT_THROW(getMachines(), UsageError);
-    settings.builders = "nix@scratchy.labs.cs.uu.nl - - 8 3 - - BAD_BASE64";
+    settings.builders.override("nix@scratchy.labs.cs.uu.nl - - 8 3 - - BAD_BASE64");
     EXPECT_THROW(getMachines(), FormatError);
 }
 
@@ -143,7 +143,7 @@ TEST(machines, getMachinesWithCorrectFileReference) {
     auto path = nix::getUnitTestDataPath("machines.valid");
     ASSERT_TRUE(pathExists(path));
 
-    settings.builders = std::string("@") + path;
+    settings.builders.override(std::string("@") + path);
     Machines actual = getMachines();
     ASSERT_THAT(actual, SizeIs(3));
     EXPECT_THAT(actual, Contains(Field(&Machine::storeUri, EndsWith("nix@scratchy.labs.cs.uu.nl"))));
@@ -155,18 +155,18 @@ TEST(machines, getMachinesWithCorrectFileReferenceToEmptyFile) {
     auto path = "/dev/null";
     ASSERT_TRUE(pathExists(path));
 
-    settings.builders = std::string("@") + path;
+    settings.builders.override(std::string("@") + path);
     Machines actual = getMachines();
     ASSERT_THAT(actual, SizeIs(0));
 }
 
 TEST(machines, getMachinesWithIncorrectFileReference) {
-    settings.builders = std::string("@") + absPath("/not/a/file");
+    settings.builders.override(std::string("@") + absPath("/not/a/file"));
     Machines actual = getMachines();
     ASSERT_THAT(actual, SizeIs(0));
 }
 
 TEST(machines, getMachinesWithCorrectFileReferenceToIncorrectFile) {
-    settings.builders = std::string("@") + nix::getUnitTestDataPath("machines.bad_format");
+    settings.builders.override(std::string("@") + nix::getUnitTestDataPath("machines.bad_format"));
     EXPECT_THROW(getMachines(), FormatError);
 }

tests/unit/libutil/config.cc

@@ -57,7 +57,7 @@ namespace nix {
         std::map<std::string, Config::SettingInfo> settings;
         Setting<std::string> setting{&config, value, "name-of-the-setting", "description"};
 
-        setting.assign("value");
+        setting.override("value");
 
         config.getSettings(settings, /* overriddenOnly = */ false);
         const auto iter = settings.find("name-of-the-setting");
@@ -131,7 +131,7 @@ namespace nix {
         {
             std::map<std::string, Config::SettingInfo> settings;
 
-            setting.set("foo");
+            setting.setDefault("foo");
             ASSERT_EQ(setting.get(), "foo");
             config.getSettings(settings, /* overriddenOnly = */ true);
             ASSERT_TRUE(settings.empty());
@@ -170,7 +170,7 @@ namespace nix {
             "name-of-the-setting",
             "description",
         };
-        setting.assign("value");
+        setting.override("value");
 
         ASSERT_EQ(config.toJSON(),
           R"#({
@@ -197,7 +197,7 @@ namespace nix {
             true,
             Xp::Flakes,
         };
-        setting.assign("value");
+        setting.override("value");
 
         ASSERT_EQ(config.toJSON(),
           R"#({