Installing pip for multiple Python versions does not work with symlinks

[MichaelKim0407]

Environment

• pip version: 10.0.1
• Python version: 2.7.14 + 3.6.4
• OS: MacOS High Sierra

Description

At the time of installation, pip, pipX, and pipX.Y will be written to /usr/local/bin. If there are existing symlinks, e.g. pip is symlinked to pipZ.W, this will overwrite pip executables for different versions and obviously break things.

Expected behavior

Remove the symlink and write a new file.

How to Reproduce

1. Install pip for Python 2.7 (python get-pip.py)
2. cd /usr/local/bin, rm pip, ln -s pip2.7 pip
3. Install pip for Python 3.6 (python3 get-pip.py)

Output

pip2.7 is now running 3.6

[pradyunsg]

FWIW, you shouldn't really be using the MacOS provided Python for development since that might cause your OS to become unstable (if you make changes to packages which break something).

[MichaelKim0407]

@pradyunsg I'm not using the system Python. In fact, the system python on High Sierra is 2.7.10, not 2.7.14

[pradyunsg]

Ah. My bad. 😅

[chrahunt]

I can't reproduce this upgrading from 10.0.1 to 19.2.1 in a venv:

repro.sh

docker run -it python sh -c 'touch /usr/local/bin/pip2.7 && ln -sf pip2.7 /usr/local/bin/pip && ls -l /usr/local/bin && curl -o /get-pip.py https://bootstrap.pypa.io/get-pip.py && python /get-pip.py; ls -l /usr/local/bin'

Output

total 112
lrwxrwxrwx 1 root staff     8 Jun 27  2018 2to3 -> 2to3-3.6
-rwxr-xr-x 1 root staff   101 Jun 27  2018 2to3-3.6
-rwxr-xr-x 1 root staff   239 Jun 27  2018 easy_install
-rwxr-xr-x 1 root staff   239 Jun 27  2018 easy_install-3.6
lrwxrwxrwx 1 root staff     5 Jun 27  2018 idle -> idle3
lrwxrwxrwx 1 root staff     7 Jun 27  2018 idle3 -> idle3.6
-rwxr-xr-x 1 root staff    99 Jun 27  2018 idle3.6
lrwxrwxrwx 1 root staff     6 Aug 10 15:58 pip -> pip2.7
-rw-r--r-- 1 root staff     0 Aug 10 15:58 pip2.7
-rwxr-xr-x 1 root staff   221 Jun 27  2018 pip3
-rwxr-xr-x 1 root staff   221 Jun 27  2018 pip3.6
lrwxrwxrwx 1 root staff     6 Jun 27  2018 pydoc -> pydoc3
lrwxrwxrwx 1 root staff     8 Jun 27  2018 pydoc3 -> pydoc3.6
-rwxr-xr-x 1 root staff    84 Jun 27  2018 pydoc3.6
lrwxrwxrwx 1 root staff     7 Jun 27  2018 python -> python3
lrwxrwxrwx 1 root staff    14 Jun 27  2018 python-config -> python3-config
lrwxrwxrwx 1 root staff     9 Jun 27  2018 python3 -> python3.6
lrwxrwxrwx 1 root staff    16 Jun 27  2018 python3-config -> python3.6-config
-rwxr-xr-x 2 root staff 33024 Jun 27  2018 python3.6
lrwxrwxrwx 1 root staff    17 Jun 27  2018 python3.6-config -> python3.6m-config
-rwxr-xr-x 2 root staff 33024 Jun 27  2018 python3.6m
-rwxr-xr-x 1 root staff  3089 Jun 27  2018 python3.6m-config
lrwxrwxrwx 1 root staff    10 Jun 27  2018 pyvenv -> pyvenv-3.6
-rwxr-xr-x 1 root staff   441 Jun 27  2018 pyvenv-3.6
-rwxr-xr-x 1 root staff   218 Jun 27  2018 wheel
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 1733k  100 1733k    0     0   9.9M      0 --:--:-- --:--:-- --:--:--  9.9M
Collecting pip
  Downloading https://files.pythonhosted.org/packages/62/ca/94d32a6516ed197a491d17d46595ce58a83cbb2fca280414e57cd86b84dc/pip-19.2.1-py2.py3-none-any.whl (1.4MB)
     |████████████████████████████████| 1.4MB 6.0MB/s
Installing collected packages: pip
  Found existing installation: pip 10.0.1
    Uninstalling pip-10.0.1:
      Successfully uninstalled pip-10.0.1
Successfully installed pip-19.2.1
Killed
total 116
lrwxrwxrwx 1 root staff     8 Jun 27  2018 2to3 -> 2to3-3.6
-rwxr-xr-x 1 root staff   101 Jun 27  2018 2to3-3.6
-rwxr-xr-x 1 root staff   239 Jun 27  2018 easy_install
-rwxr-xr-x 1 root staff   239 Jun 27  2018 easy_install-3.6
lrwxrwxrwx 1 root staff     5 Jun 27  2018 idle -> idle3
lrwxrwxrwx 1 root staff     7 Jun 27  2018 idle3 -> idle3.6
-rwxr-xr-x 1 root staff    99 Jun 27  2018 idle3.6
-rwxr-xr-x 1 root staff   220 Aug 10 15:58 pip
-rw-r--r-- 1 root staff     0 Aug 10 15:58 pip2.7
-rwxr-xr-x 1 root staff   220 Aug 10 15:58 pip3
-rwxr-xr-x 1 root staff   220 Aug 10 15:58 pip3.6
lrwxrwxrwx 1 root staff     6 Jun 27  2018 pydoc -> pydoc3
lrwxrwxrwx 1 root staff     8 Jun 27  2018 pydoc3 -> pydoc3.6
-rwxr-xr-x 1 root staff    84 Jun 27  2018 pydoc3.6
lrwxrwxrwx 1 root staff     7 Jun 27  2018 python -> python3
lrwxrwxrwx 1 root staff    14 Jun 27  2018 python-config -> python3-config
lrwxrwxrwx 1 root staff     9 Jun 27  2018 python3 -> python3.6
lrwxrwxrwx 1 root staff    16 Jun 27  2018 python3-config -> python3.6-config
-rwxr-xr-x 2 root staff 33024 Jun 27  2018 python3.6
lrwxrwxrwx 1 root staff    17 Jun 27  2018 python3.6-config -> python3.6m-config
-rwxr-xr-x 2 root staff 33024 Jun 27  2018 python3.6m
-rwxr-xr-x 1 root staff  3089 Jun 27  2018 python3.6m-config
lrwxrwxrwx 1 root staff    10 Jun 27  2018 pyvenv -> pyvenv-3.6
-rwxr-xr-x 1 root staff   441 Jun 27  2018 pyvenv-3.6
-rwxr-xr-x 1 root staff   218 Jun 27  2018 wheel

Can you confirm if you're still able to reproduce this?

[chrahunt]

Hello! It's been some time, so I will close this issue. Please let us know if you're still having any problems. Thanks!

[MichaelKim0407]

Hi @chrahunt , please see #5534