Creating a new Debian package using pbuilder: gnujump

Yet another practical packaging session, this ine on how to build a Debian package from scratch. This one too is based on the packaging tutorial and practical sessions of Lucas Nussbaum.

We are going to download the source code of gnujump from upstream, and use the pbuilder tool to package it. The advantages of pbuider is that it creates a minimal chroot jail that helps you track any dependencies you might forgot to specify in debian/control. Also it gives you the opportunity to build Debian packages on Ubuntu and vice-versa. You can also build packages for releases other than your own.

Prerequisites

A recent Debian or Ubuntu system.

Preparation of the pbuilder jail

Install pbuilder and relevant packages:

$ sudo apt-get -y install pbuilder debootstrap devscripts packaging-dev debian-keyring ubuntu-archive-keyring

NOTE: use ubuntu-keyring instead of ubuntu-archive-keyring if your build station is Ubuntu

Prepare the target environment. For example for Ubuntu trusty use can use this setup:

$ sudo pbuilder create --debootstrapopts --variant=buildd --mirror http://cy.archive.ubuntu.com/ubuntu --distribution trusty --architecture amd64 --components main --debbuildopts -mJohn Doe <john.doe@example.net>

Prepare the new package

Download the source:

$ wget https://ftp.gnu.org/gnu/gnujump/gnujump-1.0.8.tar.gz

Extract the archive and change into the source tree:

$ tar xvzf gnujump-1.0.8.tar.gz
$ cd gnujump-1.0.8/

Prepare for debian packaging

We are going to use the dh_make utility to prepare the debian directory and all the necessary files:

$ DEBFULLNAME="John Doe" DEBEMAIL="john.doe@example.net" dh_make -s -y --createorig

Check if all necessary files are there:

$ find debian/
debian/
debian/compat
 debian/manpage.1.ex
debian/preinst.ex
debian/rules
debian/gnujump.default.ex
debian/README.Debian
debian/copyright
debian/gnujump.cron.d.ex
debian/gnujump.doc-base.EX
debian/changelog
debian/README.source
debian/control
debian/menu.ex
debian/manpage.sgml.ex
debian/docs
debian/init.d.ex
debian/source
debian/source/format
debian/watch.ex
debian/postrm.ex
debian/prerm.ex
debian/manpage.xml.ex
debian/postinst.ex

Now Check the contents of the debian/changelog, debian/rules and debian/control files.

We will need to make some changes in the debian/control file:
```
Source: gnujump
Section: games
Priority: optional
Maintainer: John Doe <john .doe@example.net>
Build-Depends: debhelper (>= 9), autotools-dev, libsdl1.2-dev, libsdl-image1.2-dev, libsdl-mixer1.2-dev
Standards-Version: 3.9.5
Homepage: http://gnujump.es.gnu.org
...
```
The libsdl1.2-dev, libsdl-image1.2-dev and libsdl-mixer1.2-dev have been discovered by repeatedly compiling and failing until you get it right. The you can use the apt-cache search and apt-file search commands to discover the packages corresponding to the missing dependencies.

Edit the debian/rules file to look like this:

DH_VERBOSE = 1

DPKG_EXPORT_BUILDFLAGS = 1
include /usr/share/dpkg/default.mk

export DEB_BUILD_MAINT_OPTIONS = hardening=+all

export DEB_CFLAGS_MAINT_APPEND  = -Wall -pedantic
export DEB_LDFLAGS_MAINT_APPEND = -Wl,--as-needed

%:
        dh $@  --with autotools-dev

CFLAGS += -lm

Edit the debian/changelog, with dch -e, to look like this:

gnujump (1.0.8-1) unstable; urgency=low

  * Initial release

 -- John Doe</john><john .doe@example.net>  Mon, 22 Jun 2015 17:41:22 +0300

Build the package

Run this command from the source tree:

$ pdebuild

Give your password when asked. pdebuild will download and install all dependencies in the pbuilder jail and then build the package. Changes will be lost from the jail, the next time you use it but if all goes well, you should see these files under /var/cache/pbuilder/result:

$ ls -la /var/cache/pbuilder/result/
total 5776
drwxr-xr-x 2 root      root         4096 Ιούν 22 17:52 .
drwxr-xr-x 9 root      root         4096 Ιούν 22 11:26 ..
-rw-r--r-- 1 john john    1449 Ιούν 22 17:52 gnujump_1.0.8-1_amd64.changes
-rw-r--r-- 1 john john 1560574 Ιούν 22 17:52 <strong>gnujump_1.0.8-1_amd64.deb</strong>
-rw-rw-r-- 1 john john    9228 Ιούν 22 17:52 gnujump_1.0.8-1.debian.tar.xz
-rw-rw-r-- 1 john john     885 Ιούν 22 17:52 gnujump_1.0.8-1.dsc
-rw-rw-r-- 1 john john 2508641 Ιούλ 24  2012 gnujump_1.0.8.orig.tar.gz
-rw-rw-r-- 1 john john 1814056 Ιούν 22 17:41 gnujump_1.0.8.orig.tar.xz

Checking the result

View the information related to the package file:

$ dpkg -I /var/cache/pbuilder/result/gnujump_1.0.8-1_amd64.deb
new debian package, version 2.0.
size 1560574 bytes: control archive=5550 bytes.
    419 bytes,    11 lines      control              
  18390 bytes,   233 lines      md5sums              
Package: gnujump
Version: 1.0.8-1
Architecture: amd64
Maintainer: John Doe </john><john .doe@example.net>
Installed-Size: 2355
Depends: libc6 (>= 2.14), libgl1-mesa-glx | libgl1, libsdl-image1.2 (>= 1.2.10), libsdl-mixer1.2, libsdl1.2debian (>= 1.2.11)
Section: games
Priority: optional
Homepage: http://gnujump.es.gnu.org
Description: <insert up to 60 chars description>
 </insert><insert long description, indented with spaces>

As you can see our work is not finished. We need to add a description in debian/control and rebuild it.

Check the contents of the package file:

$ dpkg -I /var/cache/pbuilder/result/gnujump_1.0.8-1_amd64.deb

Install the package

Now we can install the package:

$ sudo dpkg -i /var/cache/pbuilder/result/gnujump_1.0.8-1_amd64.deb

Now run the gnujump software and check if it works.

This is not the whole story of course. You have to check the package against Lintian to see if it complies with the Debian Policy. And if it’s not compliant, you may need to use Quilt to patch it. You will need to fill debian/watch so you can track updates on the upstream with uscan. The work of a Debian packager never ends.

References

https://wiki.ubuntu.com/PbuilderHowto
https://www.debian.org/doc/manuals/packaging-tutorial/packaging-tutorial.en.pdf</insert></john>