diff --git a/src/libstore/build/derivation-goal.cc b/src/libstore/build/derivation-goal.cc
index 5de159b2d..765df5f5a 100644
--- a/src/libstore/build/derivation-goal.cc
+++ b/src/libstore/build/derivation-goal.cc
@@ -127,11 +127,15 @@ Goal::WorkResult DerivationGoal::timedOut(Error && ex)
 
 kj::Promise<Result<Goal::WorkResult>> DerivationGoal::workImpl() noexcept
 {
-    return (useDerivation ? getDerivation() : haveDerivation()).attach(kj::defer([this] {
+    KJ_DEFER({
         act.reset();
         actLock.reset();
         builderActivities.clear();
-    }));
+    });
+
+    BOOST_OUTCOME_CO_TRY(auto result, co_await (useDerivation ? getDerivation() : haveDerivation()));
+    result.storePath = drvPath;
+    co_return result;
 }
 
 bool DerivationGoal::addWantedOutputs(const OutputsSpec & outputs)
diff --git a/src/libstore/build/entry-points.cc b/src/libstore/build/entry-points.cc
index 2e91b1778..13112d827 100644
--- a/src/libstore/build/entry-points.cc
+++ b/src/libstore/build/entry-points.cc
@@ -33,10 +33,8 @@ void Store::buildPaths(const std::vector<DerivedPath> & reqs, BuildMode buildMod
                 ex = result.ex;
         }
         if (result.exitCode != Goal::ecSuccess) {
-            if (auto i2 = dynamic_cast<DerivationGoal *>(i.get()))
-                failed.insert(printStorePath(i2->drvPath));
-            else if (auto i2 = dynamic_cast<PathSubstitutionGoal *>(i.get()))
-                failed.insert(printStorePath(i2->storePath));
+            if (result.storePath)
+                failed.insert(printStorePath(*result.storePath));
         }
     }
 
diff --git a/src/libstore/build/goal.hh b/src/libstore/build/goal.hh
index 29540dcd3..5b66a2c08 100644
--- a/src/libstore/build/goal.hh
+++ b/src/libstore/build/goal.hh
@@ -94,6 +94,9 @@ public:
         bool timedOut = false;
         bool hashMismatch = false;
         bool checkMismatch = false;
+        /// Store path this goal relates to. Will be set to drvPath for
+        /// derivations, or the substituted store path for substitions.
+        std::optional<StorePath> storePath = {};
     };
 
 protected:
diff --git a/src/libstore/build/substitution-goal.cc b/src/libstore/build/substitution-goal.cc
index e0ca23a86..2d0c594ac 100644
--- a/src/libstore/build/substitution-goal.cc
+++ b/src/libstore/build/substitution-goal.cc
@@ -3,6 +3,7 @@
 #include "nar-info.hh"
 #include "signals.hh"
 #include "finally.hh"
+#include <boost/outcome/try.hpp>
 #include <kj/array.h>
 #include <kj/vector.h>
 
@@ -54,7 +55,7 @@ try {
 
     /* If the path already exists we're done. */
     if (!repair && worker.store.isValidPath(storePath)) {
-        return {done(ecSuccess, BuildResult::AlreadyValid)};
+        co_return done(ecSuccess, BuildResult::AlreadyValid);
     }
 
     if (settings.readOnlyMode)
@@ -62,9 +63,11 @@ try {
 
     subs = settings.useSubstitutes ? getDefaultSubstituters() : std::list<ref<Store>>();
 
-    return tryNext();
+    BOOST_OUTCOME_CO_TRY(auto result, co_await tryNext());
+    result.storePath = storePath;
+    co_return result;
 } catch (...) {
-    return {std::current_exception()};
+    co_return result::failure(std::current_exception());
 }