Comment 4 for bug 708828

And my instance turned out to be slightly different so sorry for the noise.

~ # python2.7 setup.py build -b build-2.7 install

Traceback (most recent call last):
  File "setup.py", line 81, in <module>
    cmdclass={'install': InstallAndUpdateDataDirectory, 'build_icons':build_icons, 'build':build_extra}
  File "/usr/lib64/python2.7/site-packages/DistUtilsExtra/auto.py", line 100, in setup
    distutils.core.setup(**attrs)
  File "/usr/lib64/python2.7/distutils/core.py", line 112, in setup
    _setup_distribution = dist = klass(attrs)
  File "/usr/lib64/python2.7/distutils/dist.py", line 259, in __init__
    getattr(self.metadata, "set_" + key)(val)
  File "/usr/lib64/python2.7/distutils/dist.py", line 1229, in set_provides
    distutils.versionpredicate.split_provision(v)
  File "/usr/lib64/python2.7/distutils/versionpredicate.py", line 160, in split_provision
    raise ValueError("illegal provides specification: %r" % value)
ValueError: illegal provides specification: 'build-2.7.lib.pithos'

Worked around by specifying the build directory name with no numbers, like this:
~ # python2.7 setup.py build -b build install