This Debian packaging must first be configured before building.

By default, all threads are disabled; package builders MUST enable
thread package builds by adding flags to the debin/configure command
line.  See `debian/configure -h` for details.

Xenomai and RTAI kernel threads packages may be enabled with the '-X
<Xenomai-kernel-version>' and '-R <RTAI-kernel-version>' options,
respectively, e.g. '-X 3.8-1mk-xenomai.x86-686-pae'.  Multiple
'-X'/'-R' options may be specified to build multiple kernel threads
packages against multiple kernels.