mpvScripts.buildLua: Expose `meta.position`

Undocumented in the nixpkgs manual, but apparently needed for `common-updaters`
and related tools such as `nix-update`.

1 files changed, 12 insertions, 1 deletions

diff --git a/pkgs/applications/video/mpv/scripts/buildLua.nix b/pkgs/applications/video/mpv/scripts/buildLua.nix
index 4c1e1957c097..c92cdc96f29f 100644
--- a/pkgs/applications/video/mpv/scripts/buildLua.nix
+++ b/pkgs/applications/video/mpv/scripts/buildLua.nix
@@ -56,6 +56,17 @@ lib.makeOverridable (args: stdenvNoCC.mkDerivation (extendedBy
     '';
 
     passthru = { inherit scriptName; };
-    meta.platforms = lib.platforms.all;
+    meta = {
+      platforms = lib.platforms.all;
+    } // (
+      let pos =
+        if (args.meta or {}) ? description then
+          builtins.unsafeGetAttrPos "description" args.meta
+        else
+          builtins.unsafeGetAttrPos "pname" args;
+      in lib.optionalAttrs
+        (pos != null)
+        { position = "${pos.file}:${toString pos.line}"; }
+    );
   })
 ))