[C++-sig] exec test failure

I submitted a new test that runs the new 'exec' and 'exec_file' functions. I tested it locally (obviously), but now I see it fail (http://engineering.meta-comm.com/boost-regression/CVS-HEAD/developer/python....). The error is always the same 'RuntimeError: exec.py : no such file', which I don't understand. The file is checked into the libs/python/test/ directory. Could somebody with more insight into the boost.build logic and Jamfile syntax please help ? Thanks, Stefan