Uploading a new release of one of my libraries to PYPI I got this error:

"""
Submitting dist/bsddb3-5.1.1.tar.gz to http://pypi.python.org/pypi
Upload failed (400): A file named "bsddb3-5.1.1.tar.gz" already exists for  bsddb3-5.1.1. To fix problems with that file you should create a new release.
Traceback (most recent call last):
  File "setup.py", line 5, in <module>
    import setup2
  File "/home/pybsddb/setup2.py", line 415, in <module>
    'Programming Language :: Python :: 3.2',
  File "/usr/local/lib/python2.7/distutils/core.py", line 152, in setup
    dist.run_commands()
  File "/usr/local/lib/python2.7/distutils/dist.py", line 953, in run_commands
    self.run_command(cmd)
  File "/usr/local/lib/python2.7/distutils/dist.py", line 972, in run_command
    cmd_obj.run()
  File "/usr/local/lib/python2.7/distutils/command/upload.py", line 60, in run
    self.upload_file(command, pyversion, filename)
  File "/usr/local/lib/python2.7/distutils/command/upload.py", line 189, in upload_file
    self.announce('-'*75, result.read(), '-'*75)
UnboundLocalError: local variable 'result' referenced before assignment
"""

Checking the code, I see this:

"""
        # send the data
        try:
            result = urlopen(request)
            status = result.getcode()
            reason = result.msg
        except socket.error, e:
            self.announce(str(e), log.ERROR)
            return
        except HTTPError, e:
            status = e.code
            reason = e.msg

        if status == 200:
            self.announce('Server response (%s): %s' % (status, reason),
                          log.INFO)
        else:
            self.announce('Upload failed (%s): %s' % (status, reason),
                          log.ERROR)
        if self.show_response:
            self.announce('-'*75, result.read(), '-'*75)
"""

Here, if we selected "show_response" *AND* some error happens, "result" will be undefined and the last line will fail.

This bug was introduced in Python 2.7. It used to work correctly under Python 2.6.

I didn't check Python 3.x.

I think this bug is trivial to reproduce: just try to upload any file with no permissions for it, using "--show_response" command line option.