LinuxQuestions.org - Do not manage to get apt-get build-depend to work!

I am currently trying to rebuilt the freetype library in order to improve character rendering. I am using ubuntu 4.10 Warty (based on a debian) with installed freetype 2.1.7-2.1ubuntu1 (don't know the difference with regular 2.1.7 version).

To do so, I launched the following command set:
apt-get --build source freetype=2.1.7-2.1ubuntu1
I get an error mentionning that dependencies are missing for correct build, so I launch the following command:
apt-get build-dep freetype=2.1.7-2.1ubuntu1
Everything goes fine till the construction of the dependency tree, but I get an error afterwards mentionning that dependencies cannot be satisfied.

dsc file mention the following:

Code:

Source: freetype

Version: 2.1.7-2.1ubuntu1

Binary: libfreetype6-udeb, libfreetype6-dev, freetype2-demos, libfreetype6

Maintainer: Anthony Fok <foka@debian.org>

Architecture: any

Standards-Version: 3.6.1

Build-Depends: debhelper (>= 4.0.0), bzip2, gettext (>= 0.10.36-2), xlibs-dev, libz-dev

Files: 

 991ff86e88b075ba363e876f4ea58680 1245623 freetype_2.1.7.orig.tar.gz

 85a89c466e8c6582e248c34d4872269f 52661 freetype_2.1.7-2.1ubuntu1.diff.gz

Using the same command set with bzip2 worked fine.
Do I miss something in my config, or do I have to update all dependencies manually? If so, which package do I have to update: the regular ones or the devel ones?

I am beginning to get lost
:scratch: