Re: (fwd) Draft spec for new dpkg "triggers" feature

[Frank Küster <frank@debian.org>]

Ian Jackson <iwj@ubuntu.com> wrote:

> I hope to be able to implement such a feature at some point in the
> nearish future.  To this end I've written a draft specification which
> you can find below.  If you're interested, please read it and comment.

As far as I've been able to read it (I'm tired and stopped somewhere
just before the WORKED EXAMPLE section), this sounds great for the TeX
packages.  We've got two use cases:

- mktexlsr needs to be called whenever a file is installed in any
  subdirectory of /usr/share/texmf{,-tetex,-texlive}.

  Since this affects possibly hundreds of subdirectories, I guess this
  is a case for a non-file trigger?

- update-updmap and subsequently updmap must be called whenever a file
  changes in /etc/texmf/updmap.d.  Classical case for a file trigger, if
  I understood correcty that "file" can be a directory, too.

  However, in this case an additional feature which I didn't find would
  be great: In case the triggered action fails and the package that was
  triggered is put into failed-config state, it would be very good to
  somehow be able to know: "Which package(s) activated the trigger?".
  In fact, when updmap failed, it was sometimes due to user
  misconfiguration - then it's okay that only the basic TeX package
  which provides updmap is known.  However, an other possible reason is
  a buggy package, and in this case it would be nice to easily see which
  one triggered the updmap call.  It's only a question of convenience,
  though: If we manage to get the bug reporter's
  /var/lib/texmf/updmap.log, we'll usually know.

There's one more question here: both mktexlsr and updmap are provided by
tetex-bin and by texlive-base-bin currently, and packages which would
trigger this would (directly or often indirectly) depend on 

tetex-bin | texlive-base-bin

(I say indirectly because most of the time it's actually going to be 

tetex-bin | texlive-latex-base

where tl-latex-base Depends: tl-base-bin).

update-updmap, on the other hand, is in tex-common on which all of them
depend.  I've not though through whether the specification caters for
this - it should.

Many thanks for your work!

Regards, Frank
-- 
Dr. Frank Küster
Single Molecule Spectroscopy, Protein Folding @ Inst. f. Biochemie, Univ. Zürich
Debian Developer (teTeX/TeXLive)