libstore: have makeLocalDerivationGoal return unique_ptrs

these can be unique rather than shared because shared_ptr has a
converting constructor. preparatory refactor for something else
and not necessary on its own, and the extra allocations we must
do for shared_ptr control blocks isn't usually relevant anyway.

Change-Id: I5391715545240c6ec8e83a031206edafdfc6462f

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libstore/build/worker.hh b/src/libstore/build/worker.hh
index 925d289bf..46adaa145 100644
--- a/src/libstore/build/worker.hh
+++ b/src/libstore/build/worker.hh
@@ -245,7 +245,7 @@ public:
 private:
     std::pair<std::shared_ptr<DerivationGoal>, kj::Promise<void>> makeDerivationGoalCommon(
         const StorePath & drvPath, const OutputsSpec & wantedOutputs,
-        std::function<std::shared_ptr<DerivationGoal>()> mkDrvGoal);
+        std::function<std::unique_ptr<DerivationGoal>()> mkDrvGoal);
     std::pair<std::shared_ptr<DerivationGoal>, kj::Promise<void>> makeDerivationGoal(
         const StorePath & drvPath,
         const OutputsSpec & wantedOutputs, BuildMode buildMode = bmNormal) override;