Backporting FreeType is quite simple - you just need to recompile the Lenny version in a Etch environment. It's a nice occasion to cover the very basics.
You need to modify
debian/changelog though. Enter the
freetype-2.3.5 directory, and type:
If you want to use another editor, you can also:
EDITOR=emacs dch -i
Here's my final changelog entry:
freetype (2.3.5-1~bpo40+1) etch-backports; urgency=low * Rebuild for Debian Backports <http://www.backports.org/> (new version works with SDL_ttf, previous one was buggy) -- Sylvain Beucler <email@example.com> Mon, 10 Dec 2007 12:46:10 +0100
What did I do?
- Changed version according to bpo convention,
- the testing version was: 2.3.5-1
dchproposes by default
- I use
ORIGINALVERSION~bpoDEBIANVERSION+BACKPORTVERSION: 2.3.5-1~bpo40+1 (Etch is version 4.0)
- Changed distribution from
- Added a terse explanation
- Check my mail address.
To generate the initial changelog entry template automagically, you can use
yes | dch -D etch-backports \ --newversion $(dpkg-parsechangelog | sed -ne 's,^Version: ,,p')~bpo40+1 \ --force-bad-version -- \ "Rebuild for Debian Backports <http://www.backports.org/>"
Also add your name in
Uploaders: ..., Sylvain Beucler <firstname.lastname@example.org>
so the package will appear in your QA page.
Then, in the
freetype-2.3.5 directory, start the compilation.
debuild -us -uc
-sa debuild option: not necessary: by default, if the version ends with '0' or '1' (as 'bpo40+1' does), dpkg-buildpackage uses the existing source release (the .orig.tar.gz file must be present in the parent directory, though).
Now you can test your dar package:
sudo dpkg -i libfreetype6_2.3.5-1~bpo40+1_i386.deb
Check your changes
Check your changes using
mkdir tmp cd tmp cp ../freetype*.diff.gz . gunzip * interdiff freetype_2.3.5-1.diff freetype_2.3.5-1~bpo40+1.diff
If you see some source changes that you didn't do, then your backport is not clean (probably it's a leftover from an incomplete
make clean). Usually, just remove the current directory and extract a new clean one using
When you backport a package, it is good to track security issues that affect it and update your package accordingly.
An easy way is subscribing to the debian-security-announce mailing list, which sends a mail each time a security fix is published for Debian.
Understanding security is difficult though. For example, in the case of Freetype for Etch,
changelog.Debian mentions a fix in July 2007:
freetype (2.2.1-5+etch2) stable-security; urgency=high * debian/patches-freetype/CVE-2007-1351_pdf-overflow: address CVE-2007-1351, an integer overflow bug in the handling of BDF fonts. Closes: #426771. -- Steve Langasek <email@example.com> Mon, 09 Jul 2007 17:21:11 -0700
while the security was actually published nearly 6 months later:
- http://lists.debian.org/debian-security-announce/debian-security-announce-2008/msg00012.html (7 jan 2008)
- http://security.debian.org/debian-security/pool/updates/main/f/freetype/ (timestamp 5 jan 2008)
Once you're done with testing dependencies, it is good to compile your backport in a clean, minimal environment. pbuilder is good for this.
- First change your Debian mirror in
- Initialize a pbuilder root:
pbuilder --create --distribution=etch
- Instead of using
and get the .debs in
There are variants to pbuilder such as
cowbuilder (fast copy-on-write environement instead of extracting tarballs), qemubuilder (allow cross-compiling for other architectures) and pbuilder-uml (debootstrap and compilation without root privileges). For example:
cowbuilder --create --distribution=etch pdebuild --pbuilder cowbuilder
- if compiling from lenny, add
- you can specify an alternate chroot with
pdebuild --pbuilder cowbuilder -- --basepath /var/cache/pbuilder/base-etch.cow --debian-etch-workaround --debbuildopts '-sa'