Dear fellow emacsers.
How can we make undo work on the scratch buffer? I’m sure it is a simple configuration issue, but I’m not getting the appropriate keyword to find the relevant documentation.
Thanks a lot in advance for your help and attention…
:) /\
After checking the source, it looks like this error is triggered when the
buffer-undo-list
variable is equal tot
, which means the buffer is unmodified, or at least that this variable is not modified from thescratch
buffer.There is something else in the documentation of this variable: <If the value of the variable is t, undo information is not recorded.> Maybe you can try to fix your issue by forcing the
buffer-undo-list
variable tonil
for the elisp mode, as follow:(add-hook 'elisp-mode (lambda () (setq-local buffer-undo-list nil)))
I tried it but still no joy…
Looking at this issue I noticed 3 things that may help to pinpoint the origin…:
(setq initial-major-mode 'org-mode) (setq-default major-mode 'org-mode)
(setq-default major-mode 'org-mode)
was(setq default-major-mode 'org-mode)
. Both expressions seems indistinguishable in the resulted behavior.org-roam
mode (andread-only
mode), which is very strange, but can obviously be related and/or part of the problem. The org-roam section (my config is literate in org-mode) comes before this variables being set.What does this info may imply?
Okay, I could reproduce your situation by evaluating
(setq initial-major-mode 'org-mode) (setq-default major-mode 'org-mode)
This setup forces the scratch buffer to be in org-mode, apparently breaking most of the available keybindings for it, including the undo.
The value for the
initial-major-mode
should be kept aslisp-interaction-mode
, if your configuration requires to set it.Otherwise I would remove both of these lines all together and see if the default behavior brings back the scratch buffer to be in the expected
lisp-interaction-mode
again. The additional hook I provided in my previous post shouldn’t be needed either.