add a print statement for drv path -> builder name

Author: DieracDelta

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

@@ -263,23 +263,29 @@ Goal::Co DerivationBuildingGoal::tryToBuild()
                 : buildMode == bmCheck ? "checking outputs of '%s'"
                                        : "building '%s'",
                 worker.store.printStorePath(drvPath));
-#ifndef _WIN32 // TODO enable build hook on Windows
-        if (hook)
-            msg += fmt(" on '%s'", hook->machineName);
+
+        std::string builderName;
+#ifndef _WIN32
+        if (hook) {
+            builderName = fmt("remote builder: %s", hook->machineName);
+        } else if (builder) {
+            auto maybeUID = builder->getBuilderUID();
+            if (maybeUID)
+                builderName = fmt("localhost builder with uid: %s", std::to_string(*maybeUID));
+            else
+                builderName = "";
+        } else {
+            builderName = "";
+        }
+#else
+        builderName = "";
 #endif
+        if (builderName != "")
+            msg += fmt(" on '%s'", builderName);
+
         act = std::make_unique<Activity>(
-            *logger,
-            lvlInfo,
-            actBuild,
-            msg,
-            Logger::Fields{
-                worker.store.printStorePath(drvPath),
-#ifndef _WIN32 // TODO enable build hook on Windows
-                hook ? hook->machineName :
-#endif
-                     "",
-                1,
-                1});
+            *logger, lvlInfo, actBuild, msg, Logger::Fields{worker.store.printStorePath(drvPath), builderName, 1, 1});
+
         mcRunningBuilds = std::make_unique<MaintainCount<uint64_t>>(worker.runningBuilds);
         worker.updateProgress();
     };
@@ -1143,13 +1149,12 @@ DerivationBuildingGoal::checkPathValidity(std::map<std::string, InitialOutput> &
                 // derivation, and the output path is valid, but we don't have
                 // its realisation stored (probably because it has been built
                 // without the `ca-derivations` experimental flag).
-                worker.store.registerDrvOutput(
-                    Realisation{
-                        {
-                            .outPath = info.known->path,
-                        },
-                        drvOutput,
-                    });
+                worker.store.registerDrvOutput(Realisation{
+                    {
+                        .outPath = info.known->path,
+                    },
+                    drvOutput,
+                });
             }
         }
         if (info.known && info.known->isValid())

src/libstore/include/nix/store/build/derivation-builder.hh

@@ -180,6 +180,13 @@ struct DerivationBuilder : RestrictionContext
      * killed.
      */
     virtual bool killChild() = 0;
+
+    /**
+     * Get the builder UID.
+     *
+     * @returns the builder UID if run on localhost (e.g. if it exists).
+     */
+    virtual std::optional<uid_t> getBuilderUID() = 0;
 };
 
 struct ExternalBuilder

src/libstore/unix/build/derivation-builder.cc

@@ -415,6 +415,8 @@ class DerivationBuilderImpl : public DerivationBuilder, public DerivationBuilder
 
     bool killChild() override;
 
+    std::optional<uid_t> getBuilderUID() override;
+
 private:
 
     bool decideWhetherDiskFull();
@@ -443,14 +445,13 @@ void handleDiffHook(
     if (diffHookOpt && settings.runDiffHook) {
         auto & diffHook = *diffHookOpt;
         try {
-            auto diffRes = runProgram(
-                RunOptions{
-                    .program = diffHook,
-                    .lookupPath = true,
-                    .args = {tryA, tryB, drvPath, tmpDir},
-                    .uid = uid,
-                    .gid = gid,
-                    .chdir = "/"});
+            auto diffRes = runProgram(RunOptions{
+                .program = diffHook,
+                .lookupPath = true,
+                .args = {tryA, tryB, drvPath, tmpDir},
+                .uid = uid,
+                .gid = gid,
+                .chdir = "/"});
             if (!statusOk(diffRes.first))
                 throw ExecError(diffRes.first, "diff-hook program '%1%' %2%", diffHook, statusToString(diffRes.first));
 
@@ -494,6 +495,11 @@ bool DerivationBuilderImpl::killChild()
     return ret;
 }
 
+std::optional<uid_t> DerivationBuilderImpl::getBuilderUID()
+{
+    return (buildUser) ? std::optional<uid_t>(buildUser->getUID()) : std::nullopt;
+}
+
 SingleDrvOutputs DerivationBuilderImpl::unprepareBuild()
 {
     /* Since we got an EOF on the logger pipe, the builder is presumed
@@ -1691,11 +1697,10 @@ SingleDrvOutputs DerivationBuilderImpl::registerOutputs()
 
                     std::filesystem::rename(tmpOutput, actualPath);
 
-                    return newInfoFromCA(
-                        DerivationOutput::CAFloating{
-                            .method = dof.ca.method,
-                            .hashAlgo = wanted.algo,
-                        });
+                    return newInfoFromCA(DerivationOutput::CAFloating{
+                        .method = dof.ca.method,
+                        .hashAlgo = wanted.algo,
+                    });
                 },
 
                 [&](const DerivationOutput::CAFloating & dof) { return newInfoFromCA(dof); },
@@ -1707,11 +1712,10 @@ SingleDrvOutputs DerivationBuilderImpl::registerOutputs()
                 },
 
                 [&](const DerivationOutput::Impure & doi) {
-                    return newInfoFromCA(
-                        DerivationOutput::CAFloating{
-                            .method = doi.method,
-                            .hashAlgo = doi.hashAlgo,
-                        });
+                    return newInfoFromCA(DerivationOutput::CAFloating{
+                        .method = doi.method,
+                        .hashAlgo = doi.hashAlgo,
+                    });
                 },
 
             },