title: sudo pip install setuptools --upgrade error
body: <p>I am doing <code>pip install setuptools --upgrade</code> but getting error below</p>
  
  <pre><code>Installing collected packages: setuptools
    Found existing installation: setuptools 1.1.6
      Uninstalling setuptools-1.1.6:
  Exception:
  Traceback (most recent call last):
    File "/Library/Python/2.7/site-packages/pip-8.1.1-py2.7.egg/pip/basecommand.py", line 209, in main
      status = self.run(options, args)
    File "/Library/Python/2.7/site-packages/pip-8.1.1-py2.7.egg/pip/commands/install.py", line 317, in run
      prefix=options.prefix_path,
    File "/Library/Python/2.7/site-packages/pip-8.1.1-py2.7.egg/pip/req/req_set.py", line 726, in install
      requirement.uninstall(auto_confirm=True)
    File "/Library/Python/2.7/site-packages/pip-8.1.1-py2.7.egg/pip/req/req_install.py", line 746, in uninstall
      paths_to_remove.remove(auto_confirm)
    File "/Library/Python/2.7/site-packages/pip-8.1.1-py2.7.egg/pip/req/req_uninstall.py", line 115, in remove
      renames(path, new_path)
    File "/Library/Python/2.7/site-packages/pip-8.1.1-py2.7.egg/pip/utils/__init__.py", line 267, in renames
      shutil.move(old, new)
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 299, in move
      copytree(src, real_dst, symlinks=True)
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 208, in copytree
      raise Error, errors
  Error: [('/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/__init__.py', '/tmp/pip-rV15My-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/__init__.py', "[Errno 1] Operation not permitted: '/tmp/pip-rV15My-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/__init__.py'"), ('/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/__init__.pyc', '/tmp/pip-rV15My-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/__init__.pyc', "[Errno 1] Operation not permitted: '/tmp/pip-rV15My-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/__init__.pyc'"), ('/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/markers.py', '/tmp/pip-rV15My-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/markers.py', "[Errno 1] Operation not permitted: '/tmp/pip-rV15My-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/markers.py'"), ('/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/markers.pyc', '/tmp/pip-rV15My-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/markers.pyc', "[Errno 1] Operation not permitted: '/tmp/pip-rV15My-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/markers.pyc'"), ('/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib', '/tmp/pip-rV15My-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib', "[Errno 1] Operation not permitted: '/tmp/pip-rV15My-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib'")]
  </code></pre>
  
  <p>What am I missing? I tried sudo pip install also but didn't help.</p>