diff --git a/pkgs/test/stdenv/gcc-stageCompare.nix b/pkgs/test/stdenv/gcc-stageCompare.nix
index e5c2ed5921b3..c4a0179fb846 100644
--- a/pkgs/test/stdenv/gcc-stageCompare.nix
+++ b/pkgs/test/stdenv/gcc-stageCompare.nix
@@ -14,6 +14,7 @@
 }:
 
 assert stdenv.cc.isGNU;
+
 with pkgs;
 # rebuild gcc using the "final" stdenv
 let gcc-stageCompare = (gcc-unwrapped.override {
@@ -25,7 +26,9 @@ let gcc-stageCompare = (gcc-unwrapped.override {
     }).overrideAttrs(_: {
       NIX_OUTPATH_USED_AS_RANDOM_SEED = stdenv.cc.cc.out;
     });
-in (runCommand "gcc-stageCompare" {} ''
+in
+assert lib.assertMsg (gcc-stageCompare ? checksum) "tests-stdenv-gcc-stageCompare: No `checksum` output in `gcc-stageCompare` see conditional in `gcc/common/checksum.nix`";
+(runCommand "gcc-stageCompare" {} ''
   diff -sr ${pkgs.gcc-unwrapped.checksum}/checksums ${gcc-stageCompare.checksum}/checksums && touch $out
 '').overrideAttrs (a: {
   meta = (a.meta or { }) // { platforms = lib.platforms.linux; };