This took me a few hours to find in the mailing list and I thought I would share it with a title that people would find if googling for a solution.
I compiled a fresh copy of Xen 4.0.1 and all of the tools that come along with it. I immediately rebooted and tried to run "xm" to check the status of the system. Any variation on any xen-related command led to me something along the lines of this:
ImportError: No module named xen.xmThe cause is that xen installs all of the python tools into /usr/lib/python2.6/site-packages/ which is not by default in pythons path on a Debian (or Ubuntu) machine. After several hours of searching I found this post describing the solution.
When installing the compiled tools, pass this option to the makefile:
make install-tools PYTHON_PREFIX_ARG="--install-layout=deb"Enjoy