Re: org-assert-version considered harmful

[Ihor Radchenko <yantar92@gmail.com>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>>> - git pull  =>  switches to 9.5.5, but several .el files are left unchanged.
>>> - make autoloads  =>  this refreshes the autoloads, but the .elc files
>>>   of those .el files which didn't change still won't be recompiled.
>>
>> Isn't it a bug in the elpa scripts then?
>> If a macro definition is changed and the .elc file using that macro is
>> not changed, it still needs to be re-compiled. Otherwise, all kinds of
>> unexpected side effects may appear.
>
> Yup.  But there's no option to automatically find those dependencies in
> ELisp, and (IIRC from last time I looked at it, in many packages obeying
> such dependencies would end up introducing circular dependencies in
> the Makefile), so we'd have to depend on the package's author to provide
> a working set of file dependencies.

It would be nice to have such an option. At least, for the most critical
macros. Something similar to declare statements.

>>> PPS: Maybe instead of calling `org-assert-version` everywhere, the
>>>      `org-autoloads.el` (i.e. the file that sets up the `load-path` and
>>>      the autoloads) could look for traces of Org files in the
>>>      `load-history` and signal an error if such files are found coming
>>>      from a different directory.
>>
>> No, unfortunately.
>>
>> org-autoloads, when loaded from built-in Emacs version will not help
>> to catch newer Org libraries being loaded after built-in Org version is
>> loaded.
>
> Hmm... after new-org-autoloads.el is loaded, the old-Org files will be
> relegated to "late in the `load-path`" (i.e. after the directory that
> holds the new-Org file) and should hence not be loaded any more (unless
> someone goes through the trouble to explicitly load an old-Org files
> with an absolute file name).

I admit that I do not have sufficient knowledge about the autoload magic
Emacs uses when loading packages.

For reference, one simple way to trigger "mixed" state of Org is doing
something like:

1. emacs -Q
2. (require 'org)
3. Add the newer Org version to load-path
4. (require 'ob-python)

When and which version of org-autoloads.el will be loaded in such scenario?

-- 
Ihor Radchenko,
Org mode contributor,
Learn more about Org mode at https://orgmode.org/.
Support Org development at https://liberapay.com/org-mode,
or support my work at https://liberapay.com/yantar92