Building python2.6 for Debian Lenny

Though I am a fan of Debian and use it whenever I can in server environments it is sometimes frustrating that packages in Debian’s stable release are sometimes a tidbit outdated.

Though this generally isn’t a problem over at Inter-Actief we desperately need Python 2.6 on Debian Lenny, mainly due to the so much more excellent (and actually working) support for SSL.

After reading one hell of a lot of posts, blogs, looking around on the Debian Python project site and mail archives I concluded it would just be best and faster than actually waiting for packages by the Debian team to rebuild the python2.6 source-packages in experimental against de Debian Lenny base-system.

First and foremost I wish to express my gratitude and give credits to one of my fellow system admins at Inter-Actief and good friend Matthijs Kooijman for without his knowledge, patience and guidance it would have been one big hell for me to achieve this.

Now, let us begin…

Before we begin: this is just a guide on how one could achieve this. It might inadvertently break or cause problems on your system, though unlikely since Python 2.6 can run perfectly fine alongside 2.5. However, you have been warned, proceed at your own risk.

It all begins with creating a virtual machine with a total vanilla Debian Lenny install with the same architecture as the machine you want to install the packages on we are going to build, in my case, amd64 or as uname -m tells us, x86_64.

You can of course run these procedures directly on the target machine but since it brings quite a bunch of extra packages with it I decided to do it inside a VM to keep the target/production machine as clean as possible.

On top of that I installed openssh-server so I could log in to the VM remotely because having no clipboard support in VMWare was driving me insane.

Now, since we want to build python2.6 against the Lenny basesystem we’ll need a few things, such as gcc, python’s build-dependencies etc. We can of course issue the command apt-get build-dep python2.5 but that gave me more than I wanted and it missed a few things which are needed to build python2.6 so I installed the necessary packages manually.

apt-get install debhelper autoconf libreadline5-dev libncursesw5-dev tk8.4-dev libdb4.5-dev zlib1g-dev  blt-dev libssl-dev libbz2-dev libbluetooth-dev locales libsqlite3-dev libffi-dev mime-support libgpm2 netbase lsb-release bzip2 sharutils python-sphinx

Now thos were just the build-dependencies for Python 2.6, we also need a few tools to compile everything and build the packages:
apt-get install build-essential devscripts


Let that command run and complete, now we have everything we need to build Python 2.6 ourselves. As stated above we are going to use the Python 2.6 source packages from Experimental and build those ourselves, this ensures our packages adhere to standard Debian behaviour.

First, add the following to /etc/apt/sources.list:

deb-src http://ftp.nl.debian.org/debian/ experimental main non-free contrib

Or another mirror of your choice but make sure it has the Experimental sources, not all mirrors do.

Now run apt-get update to fetch the new package lists.

Time to get kinky!

cd /root
mkdir python26
cd python26
apt-get source python2.6
cd python2.6-2.6.4~rc1


Now, let us edit the control file so we can actually build this thing:  vim debian/control

What we need to do here is change the Mainter and the Build-Depends parameters.

• Change Maintainer: Matthias Klose to your name and address
• Change tk8.5-dev to tk8.4-dev
• Change libdb4.7-dev to libdb4.5-dev

Good, that’s it when it comes to stuff we need to change. Now, prepare for a very long compile session.

dpkg-buildpackage -us -uc -b

This, once completed, finished, done testing etc. will have create a few Debian packages (.deb) and a change-file (.changes) in the parent directory.

cd ..
ls

idle-python2.6_2.6.4~rc1-1_all.deb
libpython2.6_2.6.4~rc1-1_amd64.deb
python2.6_2.6.4~rc1-1_amd64.deb
python2.6-dbg_2.6.4~rc1-1_amd64.deb
python2.6-dev_2.6.4~rc1-1_amd64.deb
python2.6-doc_2.6.4~rc1-1_all.deb
python2.6-examples_2.6.4~rc1-1_all.deb
python2.6-minimal_2.6.4~rc1-1_amd64.deb
python2.6_2.6.4~rc1-1_amd64.changes


Congratulations, you’ve just created your very own very personal Debian Lenny compatible Python 2.6 packages.

You can now install these packages, either manually using dpkg -i python2.6-minimal_2.6.4~rc1-1_amd64.deb and so on or create your own repository, add those .deb-files to it and then add your repository to apt’s sources and just issue the install command apt-get install python2.6

If you don’t know how but want to setup your own repository, see this article: http://www.debian-administration.org/articles/286

One thing, if you import those .deb’s into your repository with reprepro by feeding it the .changes-file you’ll need to edit that file and set the Distribution: part accordingly, this should be either lenny or stable.

One last thing I’d advise you to do, edit the following file: /usr/share/python/debian_defaults and add python2.6 to the supported part, but do not set it to default as it might break stuff in Lenny itself.

The reason for doing this? All the python-* packages will need to be recompiled too, such as python-pysqlite2 which will automatically be build against all supported versions the build system is aware of and without adding Python 2.6 to the debian_defaults file you’ll be building packages for just Python 2.4 and Python 2.5 which is just plain useless.

As you might be able to see, the python-* packages do not include a python version in the package name. This is because when building the package from source it will be compiled against all versions of python known to that system and then packaged into a single .deb-file.

One problem with this is that when you put it in a repository and then use apt-get update && apt-get upgrade the package is no different from the one from Debian’s own mirrors which will get precedence.

To fix that, we’ll bump the version of the package a bit.

So, here we go again:

cd /root
mkdir python-extra
cd python-extra
apt-get source python-pysqlite2
cd python-pysqlite2-2.4.1
dch --bin-nmu Local rebuild against python2.6


Now, python-pysqlite2 has a few additional build-dependencies which we will have to install first:
apt-get install python-all-dbg python-all-dev


You can just as well run:
apt-get build-dep python-pysqlite2


That will make sure all the build-dependencies for python-pysqlite2 are satisfied which actually is a better option than manually doing it as I did before.

If you added our earlier created 2.6 packages to a repository then also issue:
apt-get install python2.6-dbg python2.6-dev


If not, make sure you install the python2.6-dev en -dbg .deb-files we created earlier.

Though in this case it is not strictly necessary to edit the debian/control-file it might be wise to do so and change once again the Maintainer: line.

Now, just as with building Python 2.6 we need to issue the following command:
dpkg-buildpackage -uc -us -b


This command will complete in quite the short time, especially compared to compiling the whole of Python 2.6.

cd ..
ls

python-pysqlite2_2.4.1-1+b1_amd64.deb
python-pysqlite2-dbg_2.4.1-1+b1_amd64.deb
python-pysqlite2_2.4.1-1+b1_amd64.changes


As you can see, our package has the +b1 attached to its packagename now which basically means to apt that our version is newer than the one provided by the Debian mirrors themselves and our package will be installed instead if added to a repository and installed through apt.

NOTE: If the Debian team should release a new version of the python-* package you will need to run this procedure again as their package will have a higher version number and override yours in an upgrade.

Now either install the package with dpkg -i python-pysqlite2_2.4.1-1+b1_amd64.deb or edit the .changes-file as we did for the Python 2.6 package and add it to your repository, update apt and install as usual.

Need another python-* module? The same principle applies for all of them.

Don’t forget to satisfy the build-dependencies of each package you want to build first, can save you quite the trouble and weird error messages. Just search for the package on http://packages.debian.org and then navigate to the source package or just issue apt-get build-dep python-packagename to have apt take care of everything for you.

Good luck and have fun!