Pero tío ¿ tú lees ? ...
"Building from Archive Files
Alternatively, the script can build the source from archive files. X.Org regularly publishes versions of the source code in the form of tarballs. The example shown involves tarballs from the X11R7.6 release. The script can also build a mixture of tarballs and source from git.
You must first download the tarballs before running the build script. An input file containing URLs to read can be provided. You do not need to extract the tarballs. A sample command:
wget http://www.x.org/releases/X11R7.6/src/util/util-macros-1.11.0.tar.gz
You are now ready to launch a full build by invoking the build script. You can leave the --clone option in, any missing source will be obtained from git, at the current development level."
No solamente "tarballs" es un link a los fuentes; además en el wget de abajo ves perfectamente la URL ...