can't use "./setup.py --home=..." to install trac locally

[Artem Baguinski <femistofel@…>]

I'd like to install trac in my home directory on a webserver I don't own. If I try to

  python setup.py install --home=~/local/stow/trac

I get:

running install
Traceback (most recent call last):
  File "setup.py", line 237, in ?
    cmdclass = {'install': my_install,
  File "/usr/lib/python2.3/distutils/core.py", line 149, in setup
    dist.run_commands()
  File "/usr/lib/python2.3/distutils/dist.py", line 907, in run_commands
    self.run_command(cmd)
  File "/usr/lib/python2.3/distutils/dist.py", line 927, in run_command
    cmd_obj.run()
  File "setup.py", line 31, in run
    self.siteconfig()
  File "setup.py", line 34, in siteconfig
    conf_dir = os.path.join(self.prefix, 'share', 'trac', 'conf')
  File "/usr/lib/python2.3/posixpath.py", line 62, in join
    elif path == '' or path.endswith('/'):
AttributeError: 'NoneType' object has no attribute 'endswith'

Because self.prefix doesn't exist. I can workaround using --prefix.

[cmlenz]

Duplicate of #963.