TypeError: dist must be a Distribution instance

Question

My package depends on BeautifulSoup. If I install my package in a fresh virtualenv via python setup.py develop, I get the following error. If I execute python setup.py develop a second time, everything seems to work fine. I have no idea, what's happening. How to fix it to get a reproducable setup?

Best match: beautifulsoup4 4.3.2
Downloading https://pypi.python.org/packages/source/b/beautifulsoup4/beautifulsoup4-4.3.2.tar.gz#md5=b8d157a204d56512a4cc196e53e7d8ee
Processing beautifulsoup4-4.3.2.tar.gz
Writing /tmp/easy_install-1eBfi3/beautifulsoup4-4.3.2/setup.cfg
Running beautifulsoup4-4.3.2/setup.py -q bdist_egg --dist-dir /tmp/easy_install-1eBfi3/beautifulsoup4-4.3.2/egg-dist-tmp-YmoFSq
Traceback (most recent call last):
  File "setup.py", line 73, in <module>
    """,
  File "/usr/lib/python2.7/distutils/core.py", line 152, in setup
    dist.run_commands()
  File "/usr/lib/python2.7/distutils/dist.py", line 953, in run_commands
    self.run_command(cmd)
  File "/usr/lib/python2.7/distutils/dist.py", line 972, in run_command
    cmd_obj.run()
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/setuptools/command/develop.py", line 27, in run
    self.install_for_development()
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/setuptools/command/develop.py", line 129, in install_for_development
    self.process_distribution(None, self.dist, not self.no_deps)
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/setuptools/command/easy_install.py", line 671, in process_distribution
    [requirement], self.local_index, self.easy_install
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/pkg_resources.py", line 564, in resolve
    dist = best[req.key] = env.best_match(req, self, installer)
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/pkg_resources.py", line 802, in best_match
    return self.obtain(req, installer) # try and download/install
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/pkg_resources.py", line 814, in obtain
    return installer(requirement)
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/setuptools/command/easy_install.py", line 593, in easy_install
    return self.install_item(spec, dist.location, tmpdir, deps)
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/setuptools/command/easy_install.py", line 623, in install_item
    dists = self.install_eggs(spec, download, tmpdir)
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/setuptools/command/easy_install.py", line 809, in install_eggs
    return self.build_and_install(setup_script, setup_base)
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/setuptools/command/easy_install.py", line 1015, in build_and_install
    self.run_setup(setup_script, setup_base, args)
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/setuptools/command/easy_install.py", line 1000, in run_setup
    run_setup(setup_script, args)
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/setuptools/sandbox.py", line 50, in run_setup
    lambda: execfile(
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/setuptools/sandbox.py", line 100, in run
    return func()
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/setuptools/sandbox.py", line 52, in <lambda>
    {'__file__':setup_script, '__name__':'__main__'}
  File "setup.py", line 27, in <module>
    'raven',
  File "/usr/lib/python2.7/distutils/core.py", line 152, in setup
    dist.run_commands()
  File "/usr/lib/python2.7/distutils/dist.py", line 953, in run_commands
    self.run_command(cmd)
  File "/usr/lib/python2.7/distutils/dist.py", line 970, in run_command
    cmd_obj = self.get_command_obj(command)
  File "/usr/lib/python2.7/distutils/dist.py", line 846, in get_command_obj
    cmd_obj = self.command_obj[command] = klass(self)
  File "/home/domma/VirtualEnvs/orcid/local/lib/python2.7/site-packages/setuptools/__init__.py", line 69, in __init__
    _Command.__init__(self,dist)
  File "/usr/lib/python2.7/distutils/cmd.py", line 59, in __init__
    raise TypeError, "dist must be a Distribution instance"
TypeError: dist must be a Distribution instance

Answer 1

This error has to do with a discrepancy between the versions of distutils and setuptools installed on your machine. Upgrading setuptools to the current version is likely to resolve the issue.

EDIT: This solution no longer works for me (and apparently never worked for Jens -- see comment below). What now works for me is to import setuptools before anything else in whatever script I'm calling that leads to this error.

This error is discussed in many issues on GitHub, in many packages, but I find this discussion to be the most informative.

Answer 2

The only way I was able to solve it was to follow the https://bugs.python.org/file37554/distutils_accomodate_distribution_ducktypes.patch So - I removed /usr/lib/python2.7/distutils/cmd.py and /usr/lib/python2.7/distutils/cmd.pyc ( ran a python setup.py develop - just to make sure it fails and is not using the pyc from somewhere else ) and then recreated /usr/lib/python2.7/distutils/cmd.py - only this time with the changes as shown in the patch. Then when I used python setup.py again - it worked..

Answer 3

install dnspython. pip install dnspython. Or check if u have older version of dnspython and upgrade

Answer 4

Try using pip for installing your package

$ pip install -e path/to/your/Project

See http://pip.readthedocs.org/en/latest/reference/pip_install.html#editable-installs for more information.

Answer 5

When I encountered this, it appeared at first glance that it was complaining that Distribution() didn't produce a Distribution instance, but that was only partly true.

setuptools provides its own Distribution, and monkeypatches it into distutils. That works in most cases, but will fail if you get a reference to Distribution before setuptools has been imported and done its magic.

The top of the script read:

from distutils.dist import Distribution

and then later we were importing and using various parts of setuptools.

The solution in my case was to do a late import in the function that uses it so Distribution was obtained after setuptools was loaded.