This is the shell session output from when I ran pip install --upgrade git+https://github.com/nyddle/pystash.git

gistfile1.txt

jerzys-mbp:~ jerzy$ pip install --upgrade git+https://github.com/nyddle/pystash.git
Downloading/unpacking git+https://github.com/nyddle/pystash.git
  Cloning https://github.com/nyddle/pystash.git to /var/folders/ds/vq3d_chn7273nfg4gnt1xylh0000gn/T/pip-iA9Uf0-build
  Running setup.py (path:/var/folders/ds/vq3d_chn7273nfg4gnt1xylh0000gn/T/pip-iA9Uf0-build/setup.py) egg_info for package from git+https://github.com/nyddle/pystash.git

Requirement already up-to-date: args>=0.1.0 in /Library/Python/2.7/site-packages (from pystash==0.0.14)
Downloading/unpacking clint>=0.3.3 from https://pypi.python.org/packages/source/c/clint/clint-0.4.1.tar.gz#md5=d0a0952bfcc5f4c5e03c36854665b298 (from pystash==0.0.14)
  Downloading clint-0.4.1.tar.gz
  Running setup.py (path:/private/var/folders/ds/vq3d_chn7273nfg4gnt1xylh0000gn/T/pip_build_jerzy/clint/setup.py) egg_info for package clint

    warning: no files found matching 'recursive-include'
    warning: no files found matching 'docs'
Downloading/unpacking requests>=2.2.0 from https://pypi.python.org/packages/2.7/r/requests/requests-2.4.3-py2.py3-none-any.whl#md5=0a66a9c4c22272680430fbb9fb4ca34f (from pystash==0.0.14)
  Downloading requests-2.4.3-py2.py3-none-any.whl (459kB): 459kB downloaded
Requirement already up-to-date: wsgiref>=0.1.2 in /System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7 (from pystash==0.0.14)
Downloading/unpacking xerox (from pystash==0.0.14)
  Downloading xerox-0.3.1.tar.gz
  Running setup.py (path:/private/var/folders/ds/vq3d_chn7273nfg4gnt1xylh0000gn/T/pip_build_jerzy/xerox/setup.py) egg_info for package xerox

Installing collected packages: clint, requests, xerox, pystash
  Found existing installation: clint 0.3.7
    Uninstalling clint:
Cleaning up...
Exception:
Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/pip-1.5.5-py2.7.egg/pip/basecommand.py", line 122, in main
    status = self.run(options, args)
  File "/Library/Python/2.7/site-packages/pip-1.5.5-py2.7.egg/pip/commands/install.py", line 283, in run
    requirement_set.install(install_options, global_options, root=options.root_path)
  File "/Library/Python/2.7/site-packages/pip-1.5.5-py2.7.egg/pip/req.py", line 1431, in install
    requirement.uninstall(auto_confirm=True)
  File "/Library/Python/2.7/site-packages/pip-1.5.5-py2.7.egg/pip/req.py", line 598, in uninstall
    paths_to_remove.remove(auto_confirm)
  File "/Library/Python/2.7/site-packages/pip-1.5.5-py2.7.egg/pip/req.py", line 1836, in remove
    renames(path, new_path)
  File "/Library/Python/2.7/site-packages/pip-1.5.5-py2.7.egg/pip/util.py", line 295, in renames
    shutil.move(old, new)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 299, in move
    rmtree(src)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 252, in rmtree
    onerror(os.remove, fullname, sys.exc_info())
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 250, in rmtree
    os.remove(fullname)
OSError: [Errno 13] Permission denied: '/Library/Python/2.7/site-packages/clint-0.3.7-py2.7.egg-info/dependency_links.txt'

Storing debug log for failure in /Users/jerzy/Library/Logs/pip.log

Hi! Thank you for the report. I'll check it out next week and will get back to you as soon as the issue is resolved.