bug#81105: 32.0.50; installed ELPA package info missing on some distros after commit 7c22a7d

> From: Philip Kaludercic <[email protected]>
> Cc: [email protected], Vonfry <[email protected]>, "'Eli Zaretskii'"
>  <[email protected]>
> Date: Fri, 31 Jul 2026 19:18:19 +0000
> 
> In `package--add-info-node' we want to avoid loading info just to add a
> directory to `Info-directory-list', so we use
> `Info-default-directory-list' instead.  The issue here is that the
> INFOPATH environmental variable is set _without_ a trailing ":", then
> `Info-default-directory-list' is ignored and we don't get any manuals
> for packages in the Info listing.  The main question is if this is
> something that we should fix by just adjusting something in package.el
> (in the worse case we can revert our change on emacs-31 and go on
> loading info) or is there a proper way to use info.el here?

I don't see how we could fix this at all, let alone in Emacs 31, to
support the case of INFOPATH not ending in a colon.  If any solution
is possible, it would mean completely rewriting the code which sets up
Info-directory-list from the known sources, and I currently don't even
have an idea how to do that without breaking all the use cases we
already support.

So at this point, I prefer to take position that we expect INFOPATH,
if set, to always end in a colon, in order to support installation of
packages with Info manual.  Since INFOPATH overrides any other builtin
settings, not ending it in a colon is dangerous (not to say
nonsensical), and distros should not do it.