elpa package autoloads

Question

I am having issues with autoloading of elpa packages under different versions of emacs (under macOS if that matters).

My ~/.emacs.d is a link to somewhere else.

Take as an example amx

The loading works under emacs 25 and 27 but not under 28. The error is like Cannot open load file: No such file or directory, ../../../../../../../.emacs.d/elpa/28/amx-20210305.118/amx.el The load-path is correct for each version

The packages are loaded into a different path for each version using this code in early-init.el

(setq package-user-dir
  (expand-file-name
   (format "elpa/%s" emacs-major-version) user-emacs-directory))

I think the issue is with the generated amx-autoloads.el file and is the last line

emacs 25 has no register-definition-prefixes

emacs 27

(if (fboundp 'register-definition-prefixes) (register-definition-prefixes "amx" '("amx-")))

emacs 28

(register-definition-prefixes "../../../../../../../.emacs.d/elpa/28/amx-20210305.118/amx" '("amx-"))

In this file the generated comments are

emacs 25 -

;;;### (autoloads nil "amx" "amx.el" (24783 47304 949021 880000))
;;; Generated autoloads from amx.el

emacs 27

;;;### (autoloads nil "amx" "../../../../../../../.emacs.d/elpa/27/amx-20210305.118/amx.el"
;;;;;;  "a034ecc8682671a85a9465e1b8dcc78e")
;;; Generated autoloads from ../../../../../../../.emacs.d/elpa/27/amx-20210305.118/amx.el

emacs 28

;;;### (autoloads nil "../../../../../../../.emacs.d/elpa/28/amx-20210305.118/amx"
;;;;;;  "../../../../../../../.emacs.d/elpa/28/amx-20210305.118/amx.el"
;;;;;;  (0 0 0 0))
;;; Generated autoloads from ../../../../../../../.emacs.d/elpa/28/amx-20210305.118/amx.el

So I think the problem is that emacs uses the relative path to a directrory in some places and uses the realpath (ie expands the symbolic link) rather than the path under ~/.emacs.d

How can I control the generation of the -autoloads.el files so that the expanded path is ideally not used as in emacs 25 or at least as in emacs 27 not really used.

I suspect that this question is the same issue but it has no answers

Answer 1

It may be corrupted byte-compilation. Delete the .elc files and recompile with v28. Keep in mind that after you do, earlier versions will not work anymore. So you might want to use a test bed to see what the outcome is, without wrecking your current production config.