Parser/asdl_c.py starts with  "#! /usr/bin/env python"  and is required
when building python.  The prevents python from being built on systems
without an existing python interpreter installed.  Which came first, the
python or the egg?

found when attempting to build python from subversion on FreeBSD 6.3.

This is what make trys to run that fails:

 ./Parser/asdl_c.py -h ./Include Parser/Python.asdl