xserver-xorg-dbg 6.8.2-10.3 (amd64 binary) in ubuntu hoary

 This package is a variant of the xserver-xorg package which includes a
 monolithic X.Org X server binary (as opposed to using loadable server
 modules on the architectures where they are supported) and which retains
 debugging symbols for execution tracing and core dump analysis.
 .
 Installation of the xserver-xorg package is recommended for documentation
 of the X.Org X server, but is not mandatory. See the package description
 of xserver-xorg for further information.