Some Questions…

Who knows debhelper?
Who packages Perl modules as .deb?
Who packages his own Perl modules as .deb?
Who knows Dist::Zilla?
Who uses Dist::Zilla for his own Perl Modules?

What is Dist::Zilla?

Dist::Zilla is "Don’t Repeat Yourself" (DRY) for Perl module authors.

Perl module distributions on CPAN require a bunch of meta data files which describe what’s in a distribution and its relations, e.g. META.yml, META,json, Makefile.PL or Build.PL. (And debhelper relies on those files, too.)
In all Perl modules you develop, you always want the same author and release tests: Checks for proper style, common errors, POD syntax and coverage, etc. (Think Lintian!)

Dist::Zilla generates all these files by gathering information from your Perl module code plus a single minimal configuration file called dist.ini.

Dist::Zilla’s command is dzil and it knows subcommands like git:

authordeps: list your distribution's author dependencies
     build: build your dist
     clean: clean up after build, test, or install
     cover: code coverage metrics for your distribution
   install: install your dist
  listdeps: print your distribution's prerequisites
   release: release your dist
       run: run stuff in a dir where your dist is built
     smoke: smoke your dist
      test: test your dist

Maintaining Debian Packages of Your Own Dist::Zilla based Perl Modules

Typical VCS-Workflow for Building .deb Packages from Your Own Perl Module

Build CPAN tar-ball from master branch with dzil build
Switch to the upstream branch
Import the contents of the tar-ball destined for CPAN into VCS
Merge the upstream branch into the debian branch
Update packaging (debian/changelog, etc.)
Build .deb package

What we want

Building the .deb directly from a VCS checkout
Skip manual tar-ball generation and reimport
Don’t commit generated files to VCS

dh-dist-zilla

Obstacles

dh-make-perl (for bootstrapping the Debian packaging) needs CPAN meta data.
- Solution: Run dh-make-perl once manually inside the dzil-generated build directory, copy debian/ subdirectory back into the project root directory.
debhelper (dh) only knows about Build.PL and Makefile.PL, not about dist.ini

Debhelper Sequence Modification

Generate build directory before debhelper looks for the existing of Build.PL or Makefile.PL.
- Call dzil build before dh_auto_configure
- Ignore generated tar ball
Build package inside the generated build directory
- Pass build directory option -D to dh_auto_configure, dh_auto_build, dh_auto_test and dh_auto_install.
Easy cleanup: Just delete the build directory.
- Call dzil clean before dh_auto_clean.

How do I use dh-dist-zilla in my Debian package?

It’s as simple as this debian/rules file:

#!/usr/bin/make -f
%:
      dh $@ --with dist-zilla

Additionally, a build-dependency on dh-dist-zilla is needed.

Untypical Workflow

Expected / Traditional:

VCS → dzil build → CPAN tar-ball ∈ Debian Source Package → Debian Binary Package

dh-dist-zilla:

VCS → dzil build → CPAN tar-ball
VCS = Debian Source Package → Debian Binary Package

Example Module/Package

Run::Parts aka librun-parts-perl

Future / Roadmap

debian/rules target to create appropriate .orig.tar.xz tar balls
dzil subcommand to call dh-make-perl in a build directory.

Links

Slides

http://noone.org/talks/pkg-perl/
Contact:
- Axel Beckert <abe@debian.org>
- Elmar Heeb <elmar@heebs.ch>

Tools

dh-dist-zilla: https://github.com/elmar/dh-dist-zilla
- Available from Debian 8 Jessie onwards: https://tracker.debian.org/pkg/dh-dist-zilla
debhelper: https://anonscm.debian.org/cgit/debhelper/debhelper.git
Dist::Zilla: http://dzil.org/
dh-make-perl: https://metacpan.org/release/DhMakePerl

From dist.ini to .deb in one go