1 files changed, 23 insertions, 0 deletions
diff --git a/src/libstore/build/goal.cc b/src/libstore/build/goal.cc
index d59b94797..ca7097a68 100644
--- a/src/libstore/build/goal.cc
+++ b/src/libstore/build/goal.cc
@@ -11,6 +11,29 @@ bool CompareGoalPtrs::operator() (const GoalPtr & a, const GoalPtr & b) const {
 }
 
 
+BuildResult Goal::getBuildResult(const DerivedPath & req) {
+    BuildResult res { buildResult };
+
+    if (auto pbp = std::get_if<DerivedPath::Built>(&req)) {
+        auto & bp = *pbp;
+
+        /* Because goals are in general shared between derived paths
+           that share the same derivation, we need to filter their
+           results to get back just the results we care about.
+         */
+
+        for (auto it = res.builtOutputs.begin(); it != res.builtOutputs.end();) {
+            if (bp.outputs.contains(it->first))
+                ++it;
+            else
+                it = res.builtOutputs.erase(it);
+        }
+    }
+
+    return res;
+}
+
+
 void addToWeakGoals(WeakGoals & goals, GoalPtr p)
 {
     if (goals.find(p) != goals.end())