tests/srcOnly: init (#347548)

pkgs/build-support/src-only/tests.nix

@@ -0,0 +1,28 @@
+{
+  runCommand,
+  srcOnly,
+  emptyDirectory,
+  glibc,
+}:
+
+let
+  emptySrc = srcOnly emptyDirectory;
+  glibcSrc = srcOnly glibc;
+in
+
+runCommand "srcOnly-tests" { } ''
+  # Test that emptySrc is empty
+  if [ -n "$(ls -A ${emptySrc})" ]; then
+    echo "emptySrc is not empty"
+    exit 1
+  fi
+
+  # Test that glibcSrc is not empty
+  if [ -z "$(ls -A ${glibcSrc})" ]; then
+    echo "glibcSrc is empty"
+    exit 1
+  fi
+
+  # Make $out exist to avoid build failure
+  mkdir -p $out
+''

pkgs/test/default.nix

@@ -170,6 +170,8 @@ with pkgs;
 
   auto-patchelf-hook = callPackage ./auto-patchelf-hook { };
 
+  srcOnly = callPackage ../build-support/src-only/tests.nix { };
+
   systemd = callPackage ./systemd { };
 
   replaceVars = recurseIntoAttrs (callPackage ./replace-vars { });