Flail at the error message

.gitlab-ci-unix.yml

@@ -24,11 +24,13 @@ spec:
 
 ".$[[ inputs.os ]]-build":
   stage: build
-  extends: .$[[ inputs.os ]]
+  extends:
+    - .$[[ inputs.os ]]
 
 ".$[[ inputs.os ]]-test":
   stage: test
-  extends: .$[[ inputs.os ]]
+  extends:
+    - .$[[ inputs.os ]]
 
 "spidermonkey-$[[ inputs.os ]]":
   extends: