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

Eli Zaretskii <[email protected]> writes:

>> From: Philip Kaludercic <[email protected]>
>> Cc: [email protected],  [email protected],  [email protected]
>> Date: Sat, 01 Aug 2026 10:21:52 +0000
>> 
>> Eli Zaretskii <[email protected]> writes:
>> 
>> >> 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.
>> 
>> So you would say that this is not a bug, and that the user is expected
>> to adjust INFOPATH on their own?
>
> Yes.
>
>> Should we document this fact
>> somewhere, as otherwise I wouldn't be surprised that many people will
>> not realize that they cannot find ELPA manuals due to some global
>> configuration.
>
> Yes, documenting this is a good idea.

We don't really talk much about Info manuals for packages in the Emacs
manual, so I suggest just adding a footnote to (emacs) Packages:

diff --git a/doc/emacs/package.texi b/doc/emacs/package.texi
index 871c5214e04..e385ae3629e 100644
--- a/doc/emacs/package.texi
+++ b/doc/emacs/package.texi
@@ -21,10 +21,13 @@ Packages
 @cindex Emacs Lisp package archive
   Packages can also be provided by @dfn{package archives}, which are
 large collections of Emacs Lisp packages.  Each package is a separate
-Emacs Lisp program, sometimes including other components such as an
-Info manual.  Emacs includes a facility that lets you easily download
-and install packages from such archives.  The rest of this chapter
-describes this facility.
+Emacs Lisp program, sometimes including other components such as an Info
+manual@footnote{Note that if your system sets the @env{INFOPATH}
+environmental variable, without a trailing path separator, then this
+shadow the manuals that Emacs registers during startup, @xref{Other Info
+Directories,,,texinfo, Texinfo}.}.  Emacs includes a facility that lets
+you easily download and install packages from such archives.  The rest
+of this chapter describes this facility.
 
   To list the packages available for installation from package
 archives, type @w{@kbd{M-x list-packages @key{RET}}}.  It brings up a