Debian/TeX Live 2015 – the new layout

While updating the TeX Live package for Debian for the upcoming 2015 release, one of my aims was to convert as much as possible of the TeX configuration infrastructure to use dpkg triggers. We used the trigger mechanism already for the update of the font map configuration file (calls to updmap-sys), but till now neither for files installed into texmf trees, nor for format generation. In this blog I will describe the new management of all TeX related configuration files, while in the following one I will describe how things have been implemented with dpkg triggers. In due time this information will also be codified in the Debian TeX sub-policy.

Let us start with recalling the different actions that have to be taken when TeX packages are installed, removed, or updated.

Required actions for TeX packages

Filename database

The simplest case are packages that only include files ment to be loaded while running TeX or Metafont or similar programs. In this case the file name database of TeX (and the one of ConTeXt) needs to be updated. Usually this is done by calling mktexlsr on the changed trees, plus, if ConTeXt is installed, running mtxrun --generate.

Font map activation

More complicated are font packages that provide PostScript fonts. These packages need to ship a so called map file which maps TeX font names to PostScript fonts names. Examples are lm.map which defines this mapping for the Latin Modern fonts. All these map files have to be collected in one or more updmap.cfg files, and then a call to updmap(-sys) is necessary to generate configuration files for dvips, pdftex, and some other programs.

Format and hyphenation definitions

Even more complicated is the case of additional hyphenation patterns and additional format definitions. At the moment, hyphenation patterns are only shipped from the TeX Live packages itself, but additional format definitions are already provided by other packages than the TeX Live ones. Again, in both cases all the different format and hyphenation pattern definitions must be combined, into configuration files fmtutil.cnf and several language.* files, respectively. After this some incantation of fmtutil(-sys) is necessary to update the format dumps of TeX.

Status up to Debian/TeX Live 2014

Up to now most of these actions are done in the postinstall script of the providing packages, generated by dh_installtex. The tex-common package shipped besides the program dh_installtex also postinstall and postrm snippets that took care of all the necessary steps, and ensuring that configuration succeeds even if some of the programs were missing.

While this worked quite nicely for many years, I saw several disadvantages:

• The postinstall script of many packages got bloated with a lot of complicated code. While this is not bad by itself, it is bad when a bug is found in this generated code because it requires a rebuild of all packages using dh_installtex.
• As before, fixes or improvements in tex-common are not picked up automatically, due to separate code.
• Package authors might forget to call dh_installtex and only install the files, which would result in unusable (for TeX) files.

Furthermore, /etc/texmf/ was filled with snippet-configuration directories, e.g., /etc/texmf/hyphen.d/ and /etc/texmf/fmt.d/ where the standard configuration of TeX was saved, and system administrators could change the necessary settings.

While this is a good thing, i.e., to give system administrators the chance to change their configuration, it carries a big risk: most system administrators, most users, have not the blankest idea how to write a proper format definition for TeX, nor a proper entry for a hyphenation pattern. And the TeX engines are not forgiving in this respect and will bail out immediately.

Finally, having so many configuration files hanging around in /etc/texmf/ makes it complicated to update between releases, where these files might have changed completely, files might have been added or removed.

New layout for Debian/TeX Live 2015 and onward

Thanks to a rewrite of fmtutil in Perl (also one of my endeavors), and adding the capability to read multiple fmtutil.cnf files in the same way updmap can read multiple updmap.cfg files, starting with Debian/TeX Live 2015 we can finally do the following:

• switch to completely trigger based activation;
• moving all format and hyphen related configuration files out of /etc/texmf/.

So let us dive into the details, following the above order:

Filename database

Update of the filename databases is now done automatically via a trigger on the two directories that are searched by kpathsea and used by Debian packages: /usr/share/texlive/texmf-dist/ (for TeX Live packages) and /usr/share/texmf/ (for all other packages).

Thus, if a Debian package installs files into one of these directories, automatically mktexlsr (and, if ConTeXt is installed also mtxrun) is run from the tex-common trigger action.

As a consequence for package maintainers of TeX related packages, if you are not adding font maps, formats, or hyphens, there is no need anymore to call dh_installtex or do anything TeX specific besides installing the files into the proper locations.

Font map activation

Here nothing has changed from the previous status, I just repeat that map snippets should be installed into /var/lib/tex-common/fontmap-cfg/texlive/ (for TeX Live packages) and /var/lib/tex-common/fontmap-cfg/texmf/ (for all other packages).

One snippet can contain arbitrary many Map or MixedMap lines. Example: /var/lib/tex-common/fontmap-cfg/texmf/tex-gyre.cfg:

Map qag.map
Map qbk.map
Map qcr.map
Map qcs.map
Map qhv.map
Map qpl.map
Map qtm.map
Map qzc.map

There is a necessary action to be taken in postinst and postrm, which is calling update-texmf-conf map (but take care when writing your own code in postrm, as update-texmf-conf might not be available!).

Format and hyphenation definitions

Format definitions and hyphenations are now treated in the very same way as font maps. That is:

• Format and hyphenation definitions need to be installed into the relevant sub-directories of /var/lib/tex-common/fmtutil-cnf/ and /var/lib/tex-common/hyphen-cnf, respectively. Relevant sub-directories here refers to either texlive (for TeX Live packages) or texmf (for all other packages), similar to the font map case.
• Maintainer scripts need to call update-texmf-conf format and update-texmf-conf hyphen, respectively.

Package maintainers are advised to use dh_installtex as it also caters for the removal of format dumps under /var/lib/texmf/web2c.

Format of the configuration files

Files under /var/lib/tex-common/fmtutil-cnf/ must consist of syntactically correct lines for fmtutil.cnf, that is white-space separated entries where the first word is the name of the format, the second the name of the engine, the third the respective hyphenation configuration file or a literal – if none, and the rest of the line are additional arguments to the respective initex program, where the last entry is the ini-file. A typical example would be /var/lib/tex-common/fmtutil-cnf/texlive/texlive-omega.cnf:

aleph aleph - *aleph.ini
lamed aleph language.dat *lambda.ini

Files under /var/lib/tex-common/hyphen-cnf have a slightly changed syntax from the ones we used to have back in /etc/texmf/hyphen.d. The new syntax is taken directly from the TeX Live database, execute statement AddHyphen. That is one line of key=value pairs, where the following keys are allowed: name, synonyms, lefthyphenmin, righthyphenmin, file, file_patterns, file_exceptions, and luaspecial. A typical example would be /var/lib/tex-common/hyphen-cnf/texlive/texlive-lang-polish.cnf:

name=polish lefthyphenmin=2 righthyphenmin=2 file=loadhyph-pl.tex file_patterns=hyph-pl.pat.txt file_exceptions=hyph-pl.hyp.txt

In addition, package maintainers that have shipped files in /etc/texmf/fmt.d or /etc/texmf/hyphen.d are advised to remove them on package upgrade, using PACKAGE.maintscript and the proper rm_conffile directive (see the musixtex package for an example.

Overriding system settings

In case an administrator wants to override any of the default setting, it has become much easier in case of font maps and formats, due to the multi-feature of the respective programs. For hyphenations a separate configuration file needs to be provided.

Overriding font maps and formats

This can be handled by dropping a updmap.cfg or fmtutil.cnf file, respectively, into either /etc/texmf/web2c/ or /usr/local/share/texmf/web2c/ (both will work). The new files will be evaluated by the respective programs (updmap(-sys) and fmtutil(-sys), respectively), and allow by default to override entries in other files. Please see the manual page of the two programs for details, or this entry for updmap and this entry for fmtutil.

Overriding hyphenation patterns

When generating the various language.* files, update-language evaluates last the file /etc/texmf/web2c/local-hyphen.cnf, which should contain hyphenation patterns in the very same format as described above. Using this entry one can add additional patterns, or override given ones.

Current status of uploads

Several packages have already been uploaded to experimental: tex-common, musixtex, context, texinfo. What remains are the TeX Live packages itself, but here we are facing two problems:

• texlive-bin has been in NEW queue for over a month, and now has been rejected due to new complains on the – since years – unchanged copyright file. Well, I had already a new version in the upload queue, which extends the copyright file. So I had to build a new -1 version and re-upload it to the NEW queue. Let us see whether this one will go through. (now accepted and in experimental!)
• There is an un-overridable lintian error which will create an auto-reject when uploading my packages. This lintian error is bogus, as reported both to the lintian maintainers and to ftp-masters. Unfortunately no reaction from ftp-masters for now, so I don’t waste anyones time uploading the packages for now.

So, in case you cannot wait for the next century to happen (or, that all the packages are accepted), and still want to give it a shot, here are the apt-get lines:

deb http://people.debian.org/~preining/TeX/ exp/
deb-src http://people.debian.org/~preining/TeX/ exp/

but be warned, there might be more changes coming in.

Warnings: First, in case you have already texlive-binaries 2015.20150524.37493-2 installed, please downgrade to the new version -1 which is now on the server. They are the same packages, only the version number has changed. Yes, and if you test it, don’t be surprised if suddenly you are left with a not-working TeX system. Don’t tell me I didn’t warn you 😉

Anyway, I hope to hear some feedback and installation reports.

Conclusion

While packaging has become easier for maintainers, and there is less clutter in /etc/texmf/, we now are depending on dpkg to call the tex-common triggers. Thus, if this happens rather often, then especially fmtutil-sys --all will be called several times. This is a slight regression from the previous setup, but paid off (IMNSHO) by the arguments given in the beginning.

That said, there will be of course a certain time of transition until the new setup has proven its merits, and bugs are ironed out. But having bugs that need to be mostly fixed only in one package, namely tex-common, seems like an easier task to me.

Enjoy.