title: Setuptools Version Conflict Error when building Python Project
body: <p>I am attempting to build a python project and I am running into a Version Conflict error with setuptools.  I receive the following error message:</p>
  
  <pre><code>An internal error occurred due to a bug in either zc.buildout or in a
  recipe being used:
  Traceback (most recent call last):
    File "/project/eggs/zc.buildout-2.2.0-py2.6.egg/zc/buildout/buildout.py", line 1942, in main
      getattr(buildout, command)(args)
    File "/project/eggs/zc.buildout-2.2.0-py2.6.egg/zc/buildout/buildout.py", line 463, in install
      self._load_extensions()
    File "/project/eggs/zc.buildout-2.2.0-py2.6.egg/zc/buildout/buildout.py", line 998, in _load_extensions
      ep.load()(self)
    File "/Users/raul/PhpstormProjects/clients/ceres/test/ceres/eggs/buildout.eggtractor-0.6-py2.6.egg/buildout/eggtractor/tractor.py", line 68, in install
      part_names = [n for n in buildout['buildout']['tractor-target-parts'].split() if n in buildout]
    File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/UserDict.py", line 105, in __contains__
      return self.has_key(key)
    File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/UserDict.py", line 100, in has_key
      value = self[key]
    File "/project/eggs/zc.buildout-2.2.0-py2.6.egg/zc/buildout/buildout.py", line 1094, in __getitem__
      options._initialize()
    File "/project/eggs/zc.buildout-2.2.0-py2.6.egg/zc/buildout/buildout.py", line 1198, in _initialize
      self.initialize()
    File "/project/eggs/zc.buildout-2.2.0-py2.6.egg/zc/buildout/buildout.py", line 1204, in initialize
      recipe_class = _install_and_load(reqs, 'zc.buildout', entry, buildout)
    File "/project/eggs/zc.buildout-2.2.0-py2.6.egg/zc/buildout/buildout.py", line 1158, in _install_and_load
      allow_hosts=buildout._allow_hosts
    File "/project/eggs/zc.buildout-2.2.0-py2.6.egg/zc/buildout/easy_install.py", line 812, in install
      return installer.install(specs, working_set)
    File "/project/eggs/zc.buildout-2.2.0-py2.6.egg/zc/buildout/easy_install.py", line 653, in install
      self._maybe_add_setuptools(ws, dist)
    File "/project/eggs/zc.buildout-2.2.0-py2.6.egg/zc/buildout/easy_install.py", line 595, in _maybe_add_setuptools
      if ws.find(requirement) is None:
    File "/Library/Python/2.6/site-packages/pkg_resources.py", line 515, in find
      raise VersionConflict(dist,req)     # XXX add more info
  VersionConflict: (setuptools 0.8 (/Library/Python/2.6/site-packages/setuptools-0.8-py2.6.egg), Requirement.parse('setuptools==0.6c11'))
  </code></pre>
  
  <p>This error is similar to the one discussed here: <a href="https://stackoverflow.com/questions/17586987/how-to-solve-pkg-resources-versionconflict-error-during-bin-python-bootstrap-py">How to solve pkg_resources.VersionConflict error during bin/python bootstrap.py -d</a></p>
  
  <p>The key difference is that my error tells me to downgrade from version 0.8 to 0.6cll, while the error in the linked post requires an upgrade to resolve the error.  </p>
  
  <p>Also note the statement: Requirement.parse('setuptools==0.6c11').  This seems to require an exact match and causes an error even though a newer version is installed.</p>
  
  <p>In fact, I have already tried downgrading to version 0.6c11, and I get the following error message:</p>
  
  <pre><code>Error: There is a version conflict.
  We already have: setuptools 0.6c11
  but distribute 0.7.3 requires 'setuptools&gt;=0.7'.
  but zc.buildout 2.2.0 requires 'setuptools&gt;=0.7'.
  </code></pre>
  
  <p>So it appears that Some Thing requires setuptoos==0.6c11 and Another Thing requires setuptools>=0.7.  I'm pretty sure I can't meet both requirements.</p>
  
  <p>I am trying to setup a development environment on a Mac OsX 10.7 and using Python version 2.6 (required by the project).  Any Idea how I can resolve this issue?</p>
  
  <p>Any help would be very welcome.</p>