pip fail after upgrade to 1.5.5

$ pip install --upgrade pip
Downloading/unpacking pip from https://pypi.python.org/packages/py2.py3/p/pip/pip-1.5.5-py2.py3-none-any.whl#md5=03a932d6f82a3887d8de1cdb837c87ed
  Using download cache from /Users/robinho/Library/Caches/pip-downloads/https%3A%2F%2Fpypi.python.org%2Fpackages%2Fpy2.py3%2Fp%2Fpip%2Fpip-1.5.5-py2.py3-none-any.whl
Installing collected packages: pip
  Found existing installation: pip 1.5.4
    Uninstalling pip:
      Successfully uninstalled pip
Successfully installed pip
Cleaning up...
$ pip
Traceback (most recent call last):
  File "/usr/local/bin/pip", line 5, in <module>
    from pkg_resources import load_entry_point
  File "/usr/local/lib/python2.7/site-packages/pkg_resources.py", line 2749, in <module>
    working_set = WorkingSet._build_master()
  File "/usr/local/lib/python2.7/site-packages/pkg_resources.py", line 446, in _build_master
    return cls._build_from_requirements(__requires__)
  File "/usr/local/lib/python2.7/site-packages/pkg_resources.py", line 459, in _build_from_requirements
    dists = ws.resolve(reqs, Environment())
  File "/usr/local/lib/python2.7/site-packages/pkg_resources.py", line 628, in resolve
    raise DistributionNotFound(req)
pkg_resources.DistributionNotFound: pip==1.5.4

Using a python installed by homebrew.

$ python --version
Python 2.7.6
$ brew --version
0.9.5
$ sw_vers
ProductName:    Mac OS X
ProductVersion: 10.9.2
BuildVersion:   13C1021

[Ivoz]

Either your pythons and paths are horribly messed up, or this might just be an old distribute/setuptools blowup.

Try these:

# Get rid of them
$ python -m pip uninstall -y setuptools
$ python -m pip uninstall -y distribute
# the next command should FAIL now because the above should be uninstalled
$ python -c "import pkg_resources"
# reinstall stuff now
$ python -m pip install -U --force-reinstall setuptools
$ python -m pip install -U --force-reinstall pip
# now check things work and are the same
$ python -m pip --version
$ pip --version
$ pip list

[gzur]

I just had this problem on Ubuntu 14.04 LTS after upgrading pip through pip.

Looked like this:

user@ubuntu_14_04_LTS:~$ pip
Traceback (most recent call last):
  File "/usr/local/bin/pip", line 5, in <module>
    from pkg_resources import load_entry_point
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2749, in <module>
    working_set = WorkingSet._build_master()
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 444, in _build_master
    ws.require(__requires__)
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 725, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 628, in resolve
    raise DistributionNotFound(req)
pkg_resources.DistributionNotFound: pip==1.5.6

After trying uninstalling both via pip and apt-get without ACTUALLY getting rid off it, I tracked down a file called pip (through which pip) in /usr/local/bin which contained the following script:

    user@ubuntu_14_04_LTS:/usr/local/bin$ cat pip
    #!/usr/bin/python
    # EASY-INSTALL-ENTRY-SCRIPT: 'pip==1.5.6','console_scripts','pip'
    __requires__ = 'pip==1.5.6'
    import sys
    from pkg_resources import load_entry_point

    if __name__ == '__main__':
        sys.exit(
            load_entry_point('pip==1.5.6', 'console_scripts', 'pip')()
        )

I just deleted this file and reinstalled with apt-get. There were actually two more files (pip2 and pip2.7) containing similar code which I deleted for good measure.

Works now.