libstore: move Goal::amDone to Worker

we still mutate goal state to store the results of any given goal run,
but now we also have that information in Worker and could in theory do
something else with it. we could return a map of goal to goal results,
which would also let us better diagnose failures of subgoals (at all).

Change-Id: I1df956bbd9fa8cc9485fb6df32918d68dda3ff48

1 files changed, 4 insertions, 1 deletions

diff --git a/src/libstore/build/derivation-goal.cc b/src/libstore/build/derivation-goal.cc
index a916da191..ab7b2b88c 100644
--- a/src/libstore/build/derivation-goal.cc
+++ b/src/libstore/build/derivation-goal.cc
@@ -1534,7 +1534,10 @@ Goal::Finished DerivationGoal::done(
         fs << worker.store.printStorePath(drvPath) << "\t" << buildResult.toString() << std::endl;
     }
 
-    return amDone(buildResult.success() ? ecSuccess : ecFailed, std::move(ex));
+    return Finished{
+        .result = buildResult.success() ? ecSuccess : ecFailed,
+        .ex = ex ? std::make_unique<Error>(std::move(*ex)) : nullptr,
+    };
 }