Bootstrapping Debian packages

I read something about dh_make again a while ago, which made me wonder, besides dh_make, how do people generally bootstrap new Debian packages. I don't think I've ever actually used dh_make for anything but experimenting. For the longest time, copying over the packaging files from some similar package worked pretty well.

Recently, however, I have applied a completely new strategy: I start with nothing, call debuild, fix the error, retry, until it works. This might sound pretty bizarre, but it works pretty well and enhances your understanding of how the packaging tools work.

Here is about how it works:

Start with nothing, call debuild, it complains:

cannot find readable debian/changelog anywhere!

Call dch --create, which says:

Cannot find debian directory!

OK, mkdir debian, call dch --create again, fill in the template. Call debuild again, now it says:

but there's no debian/rules there!

Create a debian/rules, that's easy to do by heart nowadays, at least as a start:

#!/usr/bin/make -f

%:
        dh $@

Call debuild again, now dpkg-buildpackage actually starts, but stops with:

dpkg-source: error: cannot read mypackage/debian/control: No such file or directory

At this point I'm too lazy to figure out what is necessary to put into debian/control, so let's just keep it simple and touch debian/control. At this point dpkg-source gets into a bit of trouble:

Use of uninitialized value $sourcepackage in sprintf at /usr/bin/dpkg-source line 290.

So let's put that in and also follow the subsequent advice to add debian/source/format and the Maintainer and Standards-Version fields. So far we have:

Source: mypackage
Maintainer: Peter Eisentraut <petere@debian.org>
Standards-Version: 3.9.2

The next hint of a message is:

dh: No packages to build.

This means we need a binary package stanza, so I'll just add

Package: mypackage
Architecture: any

Now debhelper complains:

dh: Compatibility levels before 5 are deprecated.

Not sure why it didn't complain about that earlier. Let's stick 8 in there.

At this point I had to do actual work and mess around with debian/rules a bit to get the package to actually build, but a few minutes later I had a functioning provisional package.

The next step is to clean up the warnings from the various dpkg-* workers:

dpkg-gencontrol: warning: missing information for output field Description
dpkg-gencontrol: warning: package mypackage: unused substitution variable ${shlibs:Depends}
dpkg-deb: warning: parsing file 'debian/mypackage/DEBIAN/control' near line 6 package 'mypackage': missing description
dpkg-genchanges: warning: missing Section for binary package mypackage; using '-'
dpkg-genchanges: warning: missing Priority for binary package mypackage; using '-'
dpkg-genchanges: warning: missing Section for source files
dpkg-genchanges: warning: missing Priority for source files

So we add Description, Depends, Section, and Priority.

And finally we have a list of complaints from Lintian to address:

W: mypackage source: debhelper-but-no-misc-depends mypackage
E: mypackage source: package-uses-debhelper-but-lacks-build-depends
W: mypackage source: package-needs-versioned-debhelper-build-depends 8
W: mypackage source: debhelper-overrides-need-versioned-build-depends (>= 7.0.50~)
E: mypackage source: temporary-debhelper-file debhelper.log
E: mypackage: no-copyright-file

The only things I added manually after that were Vcs-*, Homepage, and Enhances.

Now the only things left to do are running the thing through cowbuilder a few times and putting in all the necessary build dependencies, and writing a nice changelog entry.

Note, this method does not replace putting in some thought. But it's an interesting way to get a relatively clean package.