2 files changed, 21 insertions, 8 deletions

diff --git a/src/libstore/build/entry-points.cc b/src/libstore/build/entry-points.cc
index 13ff22f45..74eca63f3 100644
--- a/src/libstore/build/entry-points.cc
+++ b/src/libstore/build/entry-points.cc
@@ -15,7 +15,7 @@ void Store::buildPaths(const std::vector<DerivedPath> & reqs, BuildMode buildMod
 
     worker.run(goals);
 
-    StorePathSet failed;
+    StringSet failed;
     std::optional<Error> ex;
     for (auto & i : goals) {
         if (i->ex) {
@@ -26,9 +26,9 @@ void Store::buildPaths(const std::vector<DerivedPath> & reqs, BuildMode buildMod
         }
         if (i->exitCode != Goal::ecSuccess) {
             if (auto i2 = dynamic_cast<DerivationGoal *>(i.get()))
-                failed.insert(i2->drvPath);
+                failed.insert(std::string { i2->drvPath.to_string() });
             else if (auto i2 = dynamic_cast<PathSubstitutionGoal *>(i.get()))
-                failed.insert(i2->storePath);
+                failed.insert(std::string { i2->storePath.to_string()});
         }
     }
 
@@ -37,7 +37,7 @@ void Store::buildPaths(const std::vector<DerivedPath> & reqs, BuildMode buildMod
         throw std::move(*ex);
     } else if (!failed.empty()) {
         if (ex) logError(ex->info());
-        throw Error(worker.failingExitStatus(), "build of %s failed", showPaths(failed));
+        throw Error(worker.failingExitStatus(), "build of %s failed", concatStringsSep(", ", quoteStrings(failed)));
     }
 }
 
diff --git a/src/libstore/build/worker.cc b/src/libstore/build/worker.cc
index 37cb86b91..99004fba5 100644
--- a/src/libstore/build/worker.cc
+++ b/src/libstore/build/worker.cc
@@ -198,8 +198,16 @@ void Worker::childStarted(GoalPtr goal, const std::set<int> & fds,
     child.respectTimeouts = respectTimeouts;
     children.emplace_back(child);
     if (inBuildSlot) {
-        if (goal->jobCategory() == JobCategory::Substitution) nrSubstitutions++;
-        else nrLocalBuilds++;
+        switch (goal->jobCategory()) {
+        case JobCategory::Substitution:
+            nrSubstitutions++;
+            break;
+        case JobCategory::Build:
+            nrLocalBuilds++;
+            break;
+        default:
+            abort();
+        }
     }
 }
 
@@ -211,12 +219,17 @@ void Worker::childTerminated(Goal * goal, bool wakeSleepers)
     if (i == children.end()) return;
 
     if (i->inBuildSlot) {
-        if (goal->jobCategory() == JobCategory::Substitution) {
+        switch (goal->jobCategory()) {
+        case JobCategory::Substitution:
             assert(nrSubstitutions > 0);
             nrSubstitutions--;
-        } else {
+            break;
+        case JobCategory::Build:
             assert(nrLocalBuilds > 0);
             nrLocalBuilds--;
+            break;
+        default:
+            abort();
         }
     }