Weird issues since cleanup commit 18f7b1

[syl20bnr]

Hey guys,

Bear with me since I have no repro steps but I will try to explain the symptoms clearly enough for you to find a solution.

First I'm pretty sure it does not come from Spacemacs config but OTOH if I emacs -Q and require yasnippet the symptoms does not appear.

Here are the symptoms:

• Starting Emacs gives (void-function yas--load-pending-jits)
• So I tried with emacs -Q --> works
• Then I removed some configuration of Yasnippet from Spacemacs, still the error
• The error seems to be triggered as soon as I add yas-minor-mode to emacs-lisp-mode-hook
• I dug into yasnippet.el and move around some code, namely moving yas--load-pending-jits before define-minor-mode and the error disappeared and was replaced by another missing symbol used in yas--load-pending-jits
• This was pulling an endless string so I put the definition of the minor mode at the end of the file and then I got a Recursive load error.

Sorry for lacking a repro step, I will try to add one at some point. I hope this description of the symptoms will be enough and most importantly I hope to learn why those errors are triggered.

cc @monnier @npostavs

EDIT: these errors let a dangling hook in post-command-hook and prevent Emacs from being usable.

[npostavs]

Oh, I think see what it is. The change below creates a buffer in emacs-lisp-mode while loading yasnippet.el, creating this buffer starts yas-minor-mode (if you've added it to the hook), but yasnippet.el isn't completely loaded yet.

 (defvar yas--font-lock-keywords
   (append '(("^#.*$" . font-lock-comment-face))
-          lisp-font-lock-keywords-2
+          (with-temp-buffer
+            (emacs-lisp-mode)
+            (font-lock-set-defaults)
+            (if (eq t (car-safe font-lock-keywords))
+                ;; They're "compiled", so extract the source.
+                (cadr font-lock-keywords)
+              font-lock-keywords))

[syl20bnr]

Makes sense, thank you for the quick response. In the mean time we switched temporarily to the last stable version.

[syl20bnr]

Proposed fix in #674
Note that I did not have signed the paper yet so feel free to amend the author, just merge it quick if the fix is adequate.

[npostavs]

I'm thinking a smaller fix, like #676. Can you try that out and confirm it works? I was using (add-hook 'emacs-lisp-mode-hook 'yas-minor-mode) (require 'yasnippet) as a reproducer, though I'm not 100% sure it's equivalent.

[syl20bnr]

Testing it.

[syl20bnr]

Fixes the OP error but if a snippet is visited without yasnippet loaded first the following error happens:

Ignoring unknown mode `snippet-mode'
File local-variables error: (void-function snippet-mode)

[npostavs]

I added an ;;;###autoload cookie to fix that, but it seems the font lock settings don't take effect the first time with this change, hmm...

[syl20bnr]

Oh ok, I indeed tested without updating the autoload. LGTM 👍

[npostavs]

Oh ok, I indeed tested without updating the autoload.

Well yes, because I only added it after you reported the problem :)

There is still the problem of font lock not working the first time.

[monnier]

• The error seems to be triggered as soon as I add yas-minor-mode to emacs-lisp-mode-hook

Indeed, if you do that before yasnippet.el is loaded we might get
into trouble. We can probably fix this by appropriately moving things
around (i.e. make sure yas-minor-mode is defined before we do the
with-temp-buffer + emacs-lisp-mode dance), but it's probably preferable
to wrap the call to emacs-lisp-mode inside an ignore-errors.

    Stefan

[npostavs]

wrap the call to emacs-lisp-mode inside an ignore-errors.

Yeah, that seems to work better.