11. Traditional Packaging¶
The majority of this guide deals with Ubuntu Distributed Development (UDD) which utilizes the distributed version control system (DVCS) Bazaar for retrieving package sources and submitting fixes with merge proposals. This article will discuss what we will call traditional packaging methods for lack of a better word. Before Bazaar was adopted for Ubuntu development, these were the typical methods for contributing to Ubuntu.
In some cases, you may need to use these tools instead of UDD. So it is good to be familiar with them. Before you begin, you should already have read the article Getting Set Up.
11.1. Getting the Source¶
In order to get a source package, you can simply run:
$ apt-get source <package_name>
This method has some draw backs though. It downloads the version of the source
that is available on your system. You are likely running the current stable
release, but you want to contribute your change against the package in the
development release. Luckily, the ubuntu-dev-tools package provides a helper
script:
$ pull-lp-source <package_name>
By default, the latest version in the development release will be downloaded. You can also specify a version or Ubuntu release like:
$ pull-lp-source <package_name> trusty
to pull the source from the trusty release, or:
$ pull-lp-source <package_name> 1.0-1ubuntu1
to download version 1.0-1ubuntu1 of the package. For more information on the
command, see man pull-lp-source.
For our example, let’s pretend we got a bug report saying that “colour” in the
description of xicc should be “color,” and we want to fix it. (Note: This
is just an example of something to change and not really a bug.) To get the
source, run:
$ pull-lp-source xicc 0.2-3
11.2. Creating a Debdiff¶
A debdiff shows the difference between two Debian packages. The name of the
command used to generate one is also debdiff. It is part of the
devscripts package. See man debdiff for all the details. To compare two
source packages, pass the two dsc files as arguments:
$ debdiff <package_name>_1.0-1.dsc <package_name>_1.0-1ubuntu1.dsc
To continue with our example, let’s edit the debian/control and “fix” our
“bug”:
$ cd xicc-0.2
$ sed -i 's/colour/color/g' debian/control
We also must adhere to the Debian Maintainer Field Spec
and edit debian/control to replace:
Maintainer: Ross Burton <ross@debian.org>
with:
Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
XSBC-Original-Maintainer: Ross Burton <ross@debian.org>
You can use the update-maintainer tool (in the ubuntu-dev-tools package)
to do that.
Remember to document your changes in debian/changelog using dch -i and
then we can generate a new source package:
$ debuild -S
Now we can examine our changes using debdiff:
$ cd ..
$ debdiff xicc_0.2-3.dsc xicc_0.2-3ubuntu1.dsc | less
To create a patch file that you can send to others or attach to a bug report for sponsorship, run:
$ debdiff xicc_0.2-3.dsc xicc_0.2-3ubuntu1.dsc > xicc_0.2-3ubuntu1.debdiff
11.3. Applying a Debdiff¶
In order to apply a debdiff, first make sure you have the source code of the version that it was created against:
$ pull-lp-source xicc 0.2-3
Then in a terminal, change to the directory where the source was uncompressed:
$ cd xicc-0.2
A debdiff is just like a normal patch file. Apply it as usual with:
$ patch -p1 < ../xicc_0.2.2ubuntu1.debdiff