no-warn-script-location doesn't work in pip.conf when PIP_CONFIG_FILE is used

[chdiza]

Environment

• pip version: 19.0.1
• Python version: 2.7.15
• OS: macOS 10.14.3

Description

Pip appears to ignore the setting of no-warn-script-location if it's specified in pip.conf and pip.conf is in a nonstandard location (but should be read because of PIP_CONFIG_FILE pointing to it).

Expected behavior

pip install -U foo (where foo will install some executables) will install foo and there is no warning about how the newly installed exectuables aren't on my $PATH.

What actually happens is that I get the warning. Pip is ignoring this setting in my pip.conf.

Note that if I use the --no-warn-script-location flag directly on the cli, there is no warning.

How to Reproduce

1. Make a custom python 2.7.15 but where the resulting python binaries aren't on $PATH. Rather, they're symlinked into a folder that is on $PATH. Install pip using said custom python.
2. In my ~/.profile I have export PIP_CONFIG_FILE="~/somepath/pip.conf"
3. In that pip.conf I have:

[install]
upgrade = true
no-warn-script-location = true

2. Then run pip install virtualenv (e.g., the specific package doesn't seem to make a difference.)
3. Observe that I still get a warning that I explicitly asked not to get.

Output

DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7.
Collecting virtualenv
  Using cached https://files.pythonhosted.org/packages/8f/f1/c0b069ca6cb44f9681715232e6d3d65c75866dd231c5e4a88e80a46634bb/virtualenv-16.3.0-py2.py3-none-any.whl
Requirement already satisfied, skipping upgrade: setuptools>=18.0.0 in /pathtocustompy/lib/python2.7/site-packages (from virtualenv) (40.7.0)
Installing collected packages: virtualenv
  The script virtualenv is installed in '/pathtocustompy/bin' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
Successfully installed virtualenv-16.3.0

[cjerdonek]

Actually, this looks like it's another example of this: #5735 (or this #5200)
Does it work if you set the value to false?

Also see this section of the docs: https://pip.pypa.io/en/stable/user_guide/#config-file

To enable the boolean options --no-compile and --no-cache-dir, falsy values have to be used:

[chdiza]

Does it work if you set the value to false?

I didn't try that (for obvious reasons), but will try it now when I get a chance.

I did try doing warn-script-location=no, but that didn't work.

[chdiza]

Turns out, it does work. This is a funny bug! Are there plans to fix it?

[cjerdonek]

Yeah, it is funny. :) It's not so easy to fix because it's baked in and so there are backwards compatibility considerations. Many people could be relying on the current interpretation of the values.

I will mark this as a documentation issue though because I think it can be documented better (e.g. mentioned in the CLI help string for the option and the affected options enumerated in the configuration section of the pip docs).

[pradyunsg]

@cjerdonek Do you reckon this can be a place where a first time contributor can contribute?

[cjerdonek]

@pradyunsg Yes, I think so.

[pradyunsg]

This issue is a good starting point for anyone who wants to help out with pip's development -- it's simple and the process of fixing this should be a good introduction to pip's development workflow. See the discussion above to understand what the desired fix is.