emacs: enable __structuredAttrs by default in elisp build helpers

Author: jian-lin

nixos/doc/manual/release-notes/rl-2505.section.md

@@ -198,6 +198,9 @@
 
 - `pkgs.nextcloud28` has been removed since it's out of support upstream.
 
+- Emacs lisp build helpers, such as `emacs.pkgs.melpaBuild`, now enables `__structuredAttrs` by default.
+  Environment variables have to be passed via the `env` attribute.
+
 - `buildGoModule` now passes environment variables via the `env` attribute. `CGO_ENABLED` should now be specified with `env.CGO_ENABLED` when passing to buildGoModule. Direct specification of `CGO_ENABLED` is now redirected by a compatibility layer with a warning, but will become an error in future releases.
 
   Go-related environment variables previously shadowed by `buildGoModule` now results in errors when specified directly. Such variables include `GOOS` and `GOARCH`.

pkgs/applications/editors/emacs/build-support/generic.nix

@@ -61,6 +61,7 @@ lib.extendMkDerivation {
       propagatedUserEnvPkgs = finalAttrs.packageRequires ++ propagatedUserEnvPkgs;
 
       strictDeps = args.strictDeps or true;
+      __structuredAttrs = args.__structuredAttrs or true;
 
       inherit turnCompilationWarningToError ignoreCompilationError;