↪ mktmpenv -p /usr/bin/python2.7 -n
↪ mktmpenv -p /usr/bin/python2.7 -n --no-site-packages
Running virtualenv with interpreter /usr/bin/python2.7
New python executable in tmp-76937c0010af65a/bin/python2.7
Also creating executable in tmp-76937c0010af65a/bin/python
Installing setuptools, pip, wheel...done.
This is a temporary environment. It will be deleted when you run 'deactivate'.
(tmp-76937c0010af65a)↪ pip install setuptools
(tmp-76937c0010af65a)↪ python setup.py install
running install
running bdist_egg
running egg_info
writing requirements to pywikibot.egg-info/requires.txt
writing pywikibot.egg-info/PKG-INFO
writing top-level names to pywikibot.egg-info/top_level.txt
writing dependency_links to pywikibot.egg-info/dependency_links.txt
reading manifest file 'pywikibot.egg-info/SOURCES.txt'
writing manifest file 'pywikibot.egg-info/SOURCES.txt'
installing library code to build/bdist.linux-x86_64/egg
running install_lib
running build_py
Traceback (most recent call last):

File "setup.py", line 215, in <module>
  use_2to3=False
File "/usr/lib64/python2.7/distutils/core.py", line 151, in setup
  dist.run_commands()
File "/usr/lib64/python2.7/distutils/dist.py", line 953, in run_commands
  self.run_command(cmd)
File "/usr/lib64/python2.7/distutils/dist.py", line 972, in run_command
  cmd_obj.run()
File "/home/wieland/dev/virtualenvs/tmp-76937c0010af65a/lib/python2.7/site-packages/setuptools/command/install.py", line 67, in run
  self.do_egg_install()
File "/home/wieland/dev/virtualenvs/tmp-76937c0010af65a/lib/python2.7/site-packages/setuptools/command/install.py", line 109, in do_egg_install
  self.run_command('bdist_egg')
File "/usr/lib64/python2.7/distutils/cmd.py", line 326, in run_command
  self.distribution.run_command(command)
File "/usr/lib64/python2.7/distutils/dist.py", line 972, in run_command
  cmd_obj.run()
File "/home/wieland/dev/virtualenvs/tmp-76937c0010af65a/lib/python2.7/site-packages/setuptools/command/bdist_egg.py", line 160, in run
  cmd = self.call_command('install_lib', warn_dir=0)
File "/home/wieland/dev/virtualenvs/tmp-76937c0010af65a/lib/python2.7/site-packages/setuptools/command/bdist_egg.py", line 146, in call_command
  self.run_command(cmdname)
File "/usr/lib64/python2.7/distutils/cmd.py", line 326, in run_command
  self.distribution.run_command(command)
File "/usr/lib64/python2.7/distutils/dist.py", line 972, in run_command
  cmd_obj.run()
File "/home/wieland/dev/virtualenvs/tmp-76937c0010af65a/lib/python2.7/site-packages/setuptools/command/install_lib.py", line 10, in run
  self.build()
File "/usr/lib64/python2.7/distutils/command/install_lib.py", line 109, in build
  self.run_command('build_py')
File "/usr/lib64/python2.7/distutils/cmd.py", line 326, in run_command
  self.distribution.run_command(command)
File "/usr/lib64/python2.7/distutils/dist.py", line 972, in run_command
  cmd_obj.run()
File "/home/wieland/dev/virtualenvs/tmp-76937c0010af65a/lib/python2.7/site-packages/setuptools/command/build_py.py", line 46, in run
  self.build_packages()
File "/usr/lib64/python2.7/distutils/command/build_py.py", line 373, in build_packages
  self.build_module(module, module_file, package)
File "/home/wieland/dev/virtualenvs/tmp-76937c0010af65a/lib/python2.7/site-packages/setuptools/command/build_py.py", line 65, in build_module
  package)
File "/usr/lib64/python2.7/distutils/command/build_py.py", line 334, in build_module
  "'package' must be a string (dot-separated), list, or tuple")

TypeError: 'package' must be a string (dot-separated), list, or tuple

I can reproduce this on Python 2.6.5, 2.6.9, 2.7.6 and 2.7.10. The last commit I have is 9a19dcf854a33246fb3e3ec0ae491cd0093d29d5.