pip uninstall failing on Windows 10

[Awful-Leo]

Environment

• pip version: latest from Python.org as of 2020-0520-1850
• Python version: 3.8.3
• OS:Windows 10

Description

1. Download the latest version of python (together with pip) from python.org.
2. update pip in cmd with "pip install pip -U"
3. pip downloads the latest pip (ver 20.1?), then starts uninstalling my local pip(successful), and tries to install the just-downloaded version. Oops! no permission! Then I open up another cmd window with admin permission, and run "pip install pip -U". No! Because "No module named 'pip'".

Expected behavior

When uninstalling pip, temporarily stores the old pip to a temp folder maybe. If the installing of the newer version is successful, delete the temp file; if not, roll back and reinstall the original version.

How to Reproduce

Follow the above.

[McSinyx]

Hi! IMHO this should be done for all packages, i.e. if install will fail then after uninstall we should have something to revert to. For the permission case only GH-6762 might fix it.

[pradyunsg]

When uninstalling pip, temporarily stores the old pip to a temp folder maybe. If the installing of the newer version is successful, delete the temp file; if not, roll back and reinstall the original version.

pip uninstall does this already. Please provide the steps for reproductions along with the output of the commands, to help diagnose why that's not happening in your case.

Note that not all of pip's developers have access to the all OSes, so the output of the steps, are especially relevant and helpful. :)

[pfmoore]

Also,

update pip in cmd with "pip install pip -U"

The recommended way of updating pip on Windows is py -m pip install -U pip. If you do pip install -U pip you will get a permission error because the install can't update the running pip.exe wrapper.

This may or may not be relevant to the issue you're reporting, but it would be helpful if you could update your description of how to reproduce the issue so that it uses the supported approach.

[Awful-Leo]

OK, I just did it again on the newly updated windows 10 (10.0.19041) with python-3.8.2-amd64.exe.

Here's what happened after the installation from powershell.

PS C:\Users\Leo> pip -V
pip 19.2.3 from c:\program files\python38\lib\site-packages\pip (python 3.8)
PS C:\Users\Leo> pip install pip -U
Looking in indexes: https://pypi.tuna.tsinghua.edu.cn/simple
Collecting pip
  Downloading https://pypi.tuna.tsinghua.edu.cn/packages/43/84/23ed6a1796480a6f1a2d38f2802901d078266bda38388954d01d3f2e821d/pip-20.1.1-py2.py3-none-any.whl (1.5MB)
     |████████████████████████████████| 1.5MB 2.2MB/s
Installing collected packages: pip
  Found existing installation: pip 19.2.3
    Uninstalling pip-19.2.3:
ERROR: Could not install packages due to an EnvironmentError: [WinError 5] 拒绝访问。: 'c:\\program files\\python38\\lib\\site-packages\\pip-19.2.3.dist-info\\entry_points.txt'
Consider using the `--user` option or check the permissions.

WARNING: You are using pip version 19.2.3, however version 20.1.1 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.
PS C:\Users\Leo>

so I opened another powershell window with admin privilege.

PS C:\WINDOWS\system32> pip install pip -U
Looking in indexes: https://pypi.tuna.tsinghua.edu.cn/simple
Collecting pip
  Downloading https://pypi.tuna.tsinghua.edu.cn/packages/43/84/23ed6a1796480a6f1a2d38f2802901d078266bda38388954d01d3f2e821d/pip-20.1.1-py2.py3-none-any.whl (1.5MB)
     |████████████████████████████████| 1.5MB 2.2MB/s
Installing collected packages: pip
  Found existing installation: pip 19.2.3
    Uninstalling pip-19.2.3:
      Successfully uninstalled pip-19.2.3
ERROR: Could not install packages due to an EnvironmentError: [WinError 5] 拒绝访问。: 'C:\\Users\\Leo\\AppData\\Local\\Temp\\pip-uninstall-17mx4r60\\pip.exe'
Consider using the `--user` option or check the permissions.
PS C:\WINDOWS\system32> pip install pip -U
Looking in indexes: https://pypi.tuna.tsinghua.edu.cn/simple
Requirement already up-to-date: pip in c:\program files\python38\lib\site-packages (20.1.1)

OK...the update worked although there were some errors, and I'm not sure which step I did different from the last one.

I'll try to reproduce the issue again on my other laptop at office next week.

Thank you all again.

[pradyunsg]

@pfmoore This looks like the check for "is this affecting pip" needs to be improved, since we've had a change in how pip uninstall works? I'm a fair bit out of my water here though, so I'll defer to you and @uranusjr on this. :)

[uranusjr]

At this point maybe we should just add a check in install and uninstall, and hard error if pip is listed in the command line. (Clarify: I want to do this for all operating systems so tutorials/articles would be motivated to update.)

[pradyunsg]

Uhm... I think I see the issue here:

pip/src/pip/_internal/commands/install.py

Line 340 in cbdf5b1

modifying_pip = pip_req.satisfied_by is None

The conditional here is wrong. :)