Re: Bug#793067: Bug#792328: info: can no longer find the Emacs manual

[Gavin Smith]

On 2 August 2015 at 00:18, Rob Browning <address@hidden> wrote:
>> As far as I can see, Debian is creating the "problem" by distributing
>> two different versions of Emacs at the same time.  So it seems to me the
>> answer should come at the same level: Debian could have two different
>> directories with the Emacs manuals.  Then no changes are needed anywhere
>> else.
>>
>> An /etc/alternatives-like thing could specify the default, and/or mess
>> around with INFOPATH as Gavin mentions, or whatever.
>>
>> But heck, it's not up to me.  If Gavin and the Emacs maintainers can
>> implement whatever you want implemented, more power to all concerned :).
>
> Practically speaking, the issue is that we'd like to have some way to
> handle more than one flavor of Emacs (or XEmacs - which appears to be
> back in testing).
>
> For Emacs itself, this was an issue that people people cared about
> fairly strongly during the Emacs 19 to Emacs 20 transition, though
> perhaps it's less significant for the major releases since.
>
> And even ignoring the emacsen, the underlying issue seems to apply to
> other programs -- say for example GCC or Guile, where people may well
> need to have more than one major version available, and where the info
> docs may have internal links to other bundled, version-matching pages
> (i.e. calc, org, ediff,...).
>
> So I'm happy to try to accommodate whatever's recommended, but in the
> longer run, I'd like to have some supported way for people to install
> two major versions of a given program and still be able to easily
> traverse whichever documentation they're interested in from both Emacs
> and the standalone reader.

As you can tell, nothing is recommended yet. There have been some
suggestions in this discussion thread about what could be done, but as
far as I know the people who want to use multiple versions of manuals
haven't come back to say whether these suggestions will meet their
needs, or what else could work.

One observation is that the case with Emacs having many manuals for it
and associated programs is a rare case. Thus the suggestion of having
subdirectories for each Emacs version (/usr/share/info/emacs23,
/usr/share/info/emacs24, etc.) doesn't mean that there would be a huge
number of subdirectories. Other manuals could have a suffix on the
filename, like gcc-4.0.info, gcc-4.1.info, etc. The only drawback of
that would be that you wouldn't be able to access those manuals with
cross-references to the "gcc" manual. Only one manual at a time could
be accessed as "gcc", unless they were installed in multiple
directories all of which were on INFOPATH. I don't think that's a huge
problem.

Apart from that the main idea to help with multiple versions of
programs is to try to get the Info file from the same subdirectory
when following a cross-reference, so that e.g. a link followed from
/usr/share/info/emacs23/calc.info to "emacs" would go to
/usr/share/info/emacs23/emacs.info, and not to
/usr/share/info/emacs24/emacs.info. (I think I said this before; I
haven't gone and read the previous conversation on this.)

There could be a script for the users to run that would update
symlinks so the right documentation file would be given if "info
emacs" was run. As far as I have heard, there's something like that
already on Debian. I think suggestions like this have already been
made.

Debian maintainers, please tell us what you need us to do. I'd be
looking for indications that somebody would find changes useful that I
might make, because any changes I would go and implement at the moment
would only be based on my theorizing, because I haven't had a real
need to look up documentation of multiple versions of programs, and my
theorizing might not match the practical reality.

PS Is there any way of stopping the Debian bug tracker system
acknowledging my email, other than leaving it off the reply list?