Re: Fwd: errors when using org-agenda

[Max Nikulin <manikulin@gmail.com>]

On 24/10/2021 15:34, Ihor Radchenko wrote:
> Max Nikulin writes:
> 
>> `org-version' with FULL argument checks whether org and org-loaddedfs
>> are loaded from the same directory and adds "mixed installation!" to the
>> version string. `org-submit-bug-report' puts full version to the message
>> subject but it is easily to miss this warning since it is in the middle
>> of the long string.
> 
> Yes, but unfortunately it does not handle early Org loading correctly.
> 
> Try the following init.el:
> 
> (require 'org)
> (add-to-list 'load-path (expand-file-name "/path/to/newest/org-mode/lisp"))
> 
> Then run emacs -Q -l /path/to/init.el
> 
> M-x org-version does not report anything suspicious even though
> M-x org-mode will error on current main because old 'org is trying to
> load files from the new load-path.

You are right, `org-version' can not catch such case. However 
improvements of mixed install detection should be incorporated into 
`org-submit-bug-report'. I would not mind to have more prominent warning 
in the message body, maybe even with the link to the FAQ entry.

> +          (loaded-features (seq-filter
> +			    (lambda (f) (memq (alist-get 'provide f)
> +				         org-feature-list))
> +                            load-history))

Some time ago I found `featurep' function, so I am curious if there are 
reasons why it should not be used here.

If earlier loaded org modules is a problem during update and compiling 
of new sources, couldn't it be solved by `eval-when-compile'? E.g. by 
new `org-require' macro that wraps `require' and checks that the file is 
loaded from the same directory (e.g. org-loaddefs, the required file, 
and the compiled file)? The idea is that such code should not depend on 
particular package manager.