emacs: support __structuredAttrs in elisp build helpers

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

@@ -43,7 +43,9 @@ lib.extendMkDerivation {
 
           emacs --batch -Q -l "$elpa2nix" \
               -f elpa2nix-install-package \
-              "$src" "$out/share/emacs/site-lisp/elpa"
+              "$src" "$out/share/emacs/site-lisp/elpa" \
+              ${if finalAttrs.turnCompilationWarningToError then "t" else "nil"} \
+              ${if finalAttrs.ignoreCompilationError then "t" else "nil"}
 
           runHook postInstall
         '';

pkgs/applications/editors/emacs/build-support/elpa2nix.el

@@ -5,8 +5,10 @@
   (if (not noninteractive)
       (error "`elpa2nix-install-package' is to be used only with -batch"))
   (pcase command-line-args-left
-    (`(,archive ,elpa)
-     (progn (setq package-user-dir elpa)
+    (`(,archive ,elpa ,turn-compilation-warning-to-error ,ignore-compilation-error)
+     (progn (setq byte-compile-error-on-warn (string= turn-compilation-warning-to-error "t"))
+            (setq byte-compile-debug (string= ignore-compilation-error "nil"))
+            (setq package-user-dir elpa)
             (elpa2nix-install-file archive)))))
 
 (defun elpa2nix-install-from-buffer ()
@@ -31,13 +33,3 @@ The file can either be a tar file or an Emacs Lisp file."
 
 ;; Allow installing package tarfiles larger than 10MB
 (setq large-file-warning-threshold nil)
-
-(let ((flag (getenv "turnCompilationWarningToError")))
-  (when (and flag
-             ;; we do not use `string-empty-p' because it requires subr-x in Emacs <= 26
-             (not (string= flag "")))
-    (setq byte-compile-error-on-warn t)))
-
-(let ((flag (getenv "ignoreCompilationError")))
-  (when (string= flag "")
-    (setq byte-compile-debug t)))

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

@@ -185,7 +185,9 @@ lib.extendMkDerivation {
           emacs --batch -Q \
               -l "$elpa2nix" \
               -f elpa2nix-install-package \
-              "$archive" "$out/share/emacs/site-lisp/elpa"
+              "$archive" "$out/share/emacs/site-lisp/elpa" \
+              ${if finalAttrs.turnCompilationWarningToError then "t" else "nil"} \
+              ${if finalAttrs.ignoreCompilationError then "t" else "nil"}
 
           runHook postInstall
         '';