bug#69528: 30.0.50; [BUG] transient.el is not a member of package--builtin-versions

[Stefan Kangas <stefankangas@gmail.com>]

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

>>>> * lisp/emacs-lisp/lisp-mnt.el (lm-version): Prefer version in the
>>>> "Package-Version:" header.  (Bug#69528)
>>> BTW, I think this is a backward-incompatible change.
>>> Whether we want `lm-version` to return the info from `Version:` or from
>>> `Package-Version:` depends on what we want to do with it.

AFAICT, we currently use it in `lm-report-bug' and with Joseph's patch
we will use it also for `loaddefs-generate--parse-file'.

>> When do we want lm-version to return Version and not Package-Version,
>> where a (lm-header "version") wouldn't serve as a more specific
>> replacement?
>
> I don't know, but if we never want to return the value of `Version:`
> when there's a `Package-Version:` then we don't need `Package-Version:`
> either (we should just replace the `Version:` field with the content of
> `Package-Version:`).

I don't have a strong opinion, but there seems to be a mismatch between
what the code does and what the documentation says.

    "The version number comes from the ‘Package-Version’ header, if it
    exists, or from the ‘Version’ header otherwise."

    (info "(elisp) Simple Packages")