"Cannot determine Magit's version" message with straight.el

[fredericgiquel]

When magit is installed with straight.el, the following message is displayed at magit startup :

Cannot determine Magit’s version (error "/home/fred/.emacs.d/straight/build/magit/magit.elc" repo static elpa dirname hash)

How to reproduce

• Use the following init.el

;; Bootstrap straight
(defvar bootstrap-version)
(let ((bootstrap-file
       (expand-file-name "straight/repos/straight.el/bootstrap.el" user-emacs-directory))
      (bootstrap-version 5))
  (unless (file-exists-p bootstrap-file)
    (with-current-buffer
        (url-retrieve-synchronously
         "https://raw.githubusercontent.com/raxod502/straight.el/develop/install.el"
         'silent 'inhibit-cookies)
      (goto-char (point-max))
      (eval-print-last-sexp)))
  (load bootstrap-file nil 'nomessage))

;; Install magit
(straight-use-package 'magit)

• M-x magit-status on a git repository
• Check *Messages* buffer

Other informations

• Magit version : last commit from github
• Emacs version : 27.1 from Debian
• The problem seems to have been introduced by commit d173de7

[tarsius]

Probably works now ...

[fredericgiquel]

The fix works with Emacs 28. But unfortunaly, the problem persists with Emacs 27.

[tarsius]

@fredericgiquel Exact same error?

@raxod502 Can I use straight from an alternative location, so that I can avoid having to move my existing .emacs.d out of the way first. Didn't see anything in the docs.

[fredericgiquel]

Yes. Exact same error.

[fredericgiquel]

I think I better understand the cause of the error.

Before d173de7 commit, locate-library was called with "magit.el" argument and always returns the path for magit.el in the build directory of straight.
Now, (locate-library "magit") returns :

• "/home/fred/.emacs.d/straight/build/magit/magit.elc" with Emacs 27
• "/home/fred/.emacs.d/straight/build/magit/magit.el" with Emacs 28

According to locate-library documentation, the load-suffixes variable is used to determine which file extensions to search. So replacing

(setq toplib (locate-library "magit"))

by

(let ((load-suffixes (delete ".elc" load-suffixes)))
        (setq toplib (locate-library "magit")))

fixes the error with straight installation of magit (at least in my case). And I think it should work with "magit.el.gz" installation.

[tarsius]

Thanks!

[raxod502]

Can I use straight from an alternative location, so that I can avoid having to move my existing .emacs.d out of the way first. Didn't see anything in the docs

Yeah, you can. In particular you should be able to set straight-base-dir (defaults to user-emacs-directory) before running the bootstrap snippet. Unfortunately, it looks like this isn't documented at present, so I filed radian-software/straight.el#852 accordingly.

[tarsius]

Thanks!

[sunlin7]

It's seems the straight will byte-compile the magit.el to be .../build/magit/magit.elc and soft link the magit.el to be ../build/magit/magit.el,
then (locate-library "magit") got the ../build/magit/magit.elc, magit will failed to detect version for this path.
The solution is like the 9a865f1, and also compatible with some minmum distibution which only has *.elc (without *.el and *.el.gz):

     (let ((load-suffixes '(".el" ".el.gz" ".elc")))
        (setq toplib (locate-library "magit"))))

[sunlin7]

I created new PR #4526 for the fixing,
@fredericgiquel plese help verify with straight.el, thanks.

[tarsius]

Thanks!

[fredericgiquel]

@sunlin7 Your PR works with straight.el.

[sunlin7]

Thanks all of you !