Buildout's easy_installl fails when dealing with strangely named python versions

[Tiberiu Ichim]

I'm trying to specify a different python interpretor for a zc.recipe.egg part, like this:

[mypart]
recipe = zc.recipe.egg
interpretor = python26

[python26]
executable = python2.6

When running buildout, this will fail with:

Traceback (most recent call last):
  File "/home/tibi/eggs/zc.buildout-1.4.2-py2.4.egg/zc/buildout/buildout.py", line 1660, in main
    getattr(buildout, command)(args)
  File "/home/tibi/eggs/zc.buildout-1.4.2-py2.4.egg/zc/buildout/buildout.py", line 532, in install
    installed_files = self[part]._call(recipe.install)
  File "/home/tibi/eggs/zc.buildout-1.4.2-py2.4.egg/zc/buildout/buildout.py", line 1204, in _call
    return f()
  File "/home/tibi/eggs/zc.recipe.egg-1.2.2-py2.4.egg/zc/recipe/egg/egg.py", line 132, in install
    reqs, ws = self.working_set()
  File "/home/tibi/eggs/zc.recipe.egg-1.2.2-py2.4.egg/zc/recipe/egg/egg.py", line 89, in working_set
    allow_hosts=self.allow_hosts,
  File "/home/tibi/eggs/zc.buildout-1.4.2-py2.4.egg/zc/buildout/easy_install.py", line 799, in install
    allow_hosts=allow_hosts)
  File "/home/tibi/eggs/zc.buildout-1.4.2-py2.4.egg/zc/buildout/easy_install.py", line 192, in __init__
    python=_get_version(executable))
  File "/home/tibi/eggs/zc.buildout-1.4.2-py2.4.egg/zc/buildout/easy_install.py", line 92, in _get_version
    version = re.match('(\d[.]\d)([.].*\d)?$', version).group(1)
AttributeError: 'NoneType' object has no attribute 'group'

It seems that at fault is the python version returned by my python, which is Ubuntu distributed system python (notice the + sign at the end): 2.6.4+