diff --git a/pkgs/populate/default.nix b/pkgs/populate/default.nix
index 9cec154..50bceca 100644
--- a/pkgs/populate/default.nix
+++ b/pkgs/populate/default.nix
@@ -21,7 +21,7 @@ let
   '';
 
   pop.derivation = target: source: shell' target /* sh */ ''
-    nix-build -E ${quote source.text} -o ${quote target.path}
+    nix-build -E ${quote source.text} -o ${quote target.path} >&2
   '';
 
   pop.file = target: source: let