overlays/ghc.nix

@@ -3,8 +3,7 @@ let
   ghcOverride = self: super: {
     ghc = super.ghc.overrideDerivation (old: {
       src = ghcSrc;
-      rev = "head";
-      # Necessary to use a non-fetchgit src
+      # Autotools need git to find the rev of the local ghc git repo.
       nativeBuildInputs = old.nativeBuildInputs ++ [ pkgs.git ];
     });
   };