Re: Problems with desktop.el after reecent local-mior-modes changes

[Andy Moreton]

On Thu 11 Mar 2021, Lars Ingebrigtsen wrote:

> Lars Ingebrigtsen <larsi@gnus.org> writes:
>
>> Andy Moreton <andrewjmoreton@gmail.com> writes:
>>
>>> After updating master today (to commit 1d4195856b), I find that emacs
>>> built from the emacs-27 branch fails to restore a desktop save file, and
>>> complains that `local-minor-modes' is not defined as a variable.
>>
>> Say "make bootstrap".
>
> Sorry, I didn't read that closely enough.  Is this error in Emacs 27,
> when trying to restore a desktop save file made with Emacs 28?

Yes.

The odd thing is that local-minor-modes does not exist in emacs-27 and
is not mentioned in the desktop save file.

> Can you (setq debug-on-error t)?  That'll give you a backtrace that'll
> tell you where it's bugging out.  

Having bootstrapped emacs-27 from a clean tree, I see:

Debugger entered--Lisp error: (void-variable local-minor-modes)
  override-global-mode(1)
  desktop-create-buffer(208 "~/.emacs.d/init.el" "init.el" emacs-lisp-mode 
(eldoc-mode override-global-mode) 26985 (27333 nil) nil nil 
((show-trailing-whitespace . t) (buffer-display-time 24650 38542 784259 0) 
(buffer-file-coding-system . utf-8-unix)) ((mark-ring (27060 27332 27249 27205 
27300 27205 27174 27060 27332 27332 27332 27332 27251 25536 25536 26985))))
  eval-buffer(#<buffer  *load*> nil 
"c:/home/ajm/.emacs.d/desktop/.ntemacs.desktop" nil t)  ; Reading at buffer 
position 28147
  load-with-code-conversion("c:/home/ajm/.emacs.d/desktop/.ntemacs.desktop" 
"c:/home/ajm/.emacs.d/desktop/.ntemacs.desktop" t t)
  load("c:/home/ajm/.emacs.d/desktop/.ntemacs.desktop" t t t)
  desktop-read()
  #f(compiled-function () #<bytecode 0x905e172dad>)()
  run-hooks(after-init-hook delayed-warnings-hook)
  command-line()
  normal-top-level()

The `override-global-mode' minor mode is from the "bind-key" package, a
dependency of "use-package" (both from MELPA).

After some more experimentation, it seems that this is another workaround:
  (add-to-list 'desktop-minor-mode-handlers
               '(override-global-mode . ignore))

It is not obvious what is referring to `local-minor-modes' in this
setup.

    AndyM