Fix faulty reversion of my changes to unsafeDiscardOutputDependency

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 70560302ea4c..09a653002f44 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -989,7 +989,7 @@ static void prim_unsafeDiscardOutputDependency(EvalState & state, Value * * args
     PathSet context2;
     foreach (PathSet::iterator, i, context) {
         Path p = *i;
-        p = "~" + string(p, 1);
+        if (p.at(0) == '=') p = "~" + string(p, 1);
         context2.insert(p);
     }