bug#63337: [PATCH] package-vc--build-documentation: Fix relative @include statements

[Eli Zaretskii]

> Cc: 63337@debbugs.gnu.org
> From: Philip Kaludercic <philipk@posteo.net>
> Date: Sun, 07 May 2023 09:58:19 +0000
> 
> Joseph Turner <joseph@breatheoutbreathe.in> writes:
> 
> > Hello!
> >
> > Because package-vc--build-documentation exports the texinfo manual to a
> > temp file inside /tmp/ , any @include statements with relative paths
> > break the makeinfo call.
> >
> > I noticed this issue when attempting to use package-vc to install
> > org-transclusion, whose manual contains the line
> >
> > #+texinfo: @include fdl.texi
> >
> > See: 
> > https://raw.githubusercontent.com/nobiot/org-transclusion/main/docs/org-transclusion-manual.org
> >
> > The attached patch solves this problem by passing the -I flag to
> > makeinfo. From makeinfo --help:
> >
> > -I DIR                        append DIR to the @include search path.
> 
> Good catch, this should be applied to emacs-29.

Fine by me.