Where to find the XFree86 build environment?

Trying to make the 3 tablet-buttons alive I run into the following problem while trying to compile LinuxWacom, and found on the internet no solutions to it. I mean I can't find the XFree86 build environment or the Xorg SDK.

checking if wacom_drv.{o,so} should be compiled... configure: WARNING: requires Xorg SDK or XFree86 build environment, wacom_drv not built

checking for XSERVER... checking for valid Xorg SDK... "xf86Version.h missing"
Tried /usr/include, /usr/include/xorg, and /usr/xc/include

Solution: install Xserver-Xorg-Dev with syaptic package manager.