Trying to uninstall a package from another path (not prefix) with pip > 9.0

[asmodehn]

• Pip version: 9.0.1 (probably introduced from https://github.com/pypa/pip/pull/3898/files)
• Python version: 2.7
• Operating System: Ubuntu Trusty 14.04

Description:

Catkin pip a complex system managing python packages in prefixes via pythonpath (and not standard virtualenvs).

development packages are installed with -e --ignore-installed --prefix <prefix_path>.

Since upgrading to pip 9.0.1 (probably 9.0.0 as well) I get permissions errors(during an entry_point install), while pip is trying to uninstall an existing system package (in a different python path).

I would expect --ignore-installed to be respected as it used to.

That being said, I have so far been unable to isolate my issue in a clean environment...

All I have for now is this error message:

--     ... Running /home/alexv/ROS/gopher_bootstrap/build/catkin_pip_env/bin/pip install -e /home/alexv/ROS/gopher_bootstrap/src/pyros --ignore-installed --no-dependencies --prefix /home/alexv/ROS/gopher_bootstrap/devel ...
--     ... Done ... [2]: Obtaining file:///home/alexv/ROS/gopher_bootstrap/src/pyros
Installing collected packages: pyros
  Found existing installation: pyros 0.3.0
    Uninstalling pyros-0.3.0:

-- Command /home/alexv/ROS/gopher_bootstrap/build/catkin_pip_env/bin/pip install -e /home/alexv/ROS/gopher_bootstrap/src/pyros --ignore-installed --no-dependencies --prefix /home/alexv/ROS/gopher_bootstrap/devel FAILED !
CMake Error at /home/alexv/ROS/gopher_bootstrap/devel/share/catkin_pip/cmake/catkin-pip-runcmd.cmake:37 (message):
  Exception:

  Traceback (most recent call last):

    File "/home/alexv/ROS/gopher_bootstrap/build/catkin_pip_env/lib/python2.7/site-packages/pip/basecommand.py", line 215, in main
      status = self.run(options, args)
    File "/home/alexv/ROS/gopher_bootstrap/build/catkin_pip_env/lib/python2.7/site-packages/pip/commands/install.py", line 342, in run
      prefix=options.prefix_path,
    File "/home/alexv/ROS/gopher_bootstrap/build/catkin_pip_env/lib/python2.7/site-packages/pip/req/req_set.py", line 778, in install
      requirement.uninstall(auto_confirm=True)
    File "/home/alexv/ROS/gopher_bootstrap/build/catkin_pip_env/lib/python2.7/site-packages/pip/req/req_install.py", line 754, in uninstall
      paths_to_remove.remove(auto_confirm)
    File "/home/alexv/ROS/gopher_bootstrap/build/catkin_pip_env/lib/python2.7/site-packages/pip/req/req_uninstall.py", line 115, in remove
      renames(path, new_path)
    File "/home/alexv/ROS/gopher_bootstrap/build/catkin_pip_env/lib/python2.7/site-packages/pip/utils/__init__.py", line 267, in renames
      shutil.move(old, new)
    File "/usr/lib/python2.7/shutil.py", line 300, in move
      rmtree(src)
    File "/usr/lib/python2.7/shutil.py", line 252, in rmtree
      onerror(os.remove, fullname, sys.exc_info())
    File "/usr/lib/python2.7/shutil.py", line 250, in rmtree
      os.remove(fullname)

  OSError: [Errno 13] Permission denied:
  '/opt/yujin/amd64/indigo-devel/lib/python2.7/dist-packages/pyros-0.3.0-py2.7.egg-info/entry_points.txt'

I have for now pined pip down to 8.1.2, and the problem does not occur...

[asmodehn]

we might be able to work around this if #90 proves to be usable

[asmodehn]

#90 is not really usable...

It seems we need to move to use --target instead of --prefix, to avoid problems from pip 9.0.
Explanation there : pypa/pip#4243 (comment)

[asmodehn]

WIP here : #122