Set project name to UNKNOWN when empty

[uranusjr]

For compatibility with distutils. This should fix the flood of incoming reports in #9617.

[ktomk]

Solves the issue for me.

/E: my original report

[netopsengineer]

Hello, just reporting the following: Mac OS 11.2.3, using pyenv, fresh 3.9.4 install, updated PIP to 21.1, went to update setuptools and wheel and got the following, let me know if I can provide any further details that might assist you:

Successfully installed pip-21.1
❯ pip install --upgrade setuptools wheel
WARNING: Value for scheme.headers does not match. Please report this to <https://github.com/pypa/pip/issues/9617>
distutils: /Users/myUser/.pyenv/versions/3.9.4/include/python3.9/UNKNOWN
sysconfig: /Users/myUser/.pyenv/versions/3.9.4/include/python3.9
WARNING: Additional context:
user = False
home = None
root = None
prefix = None

[uranusjr]

let me know if I can provide any further details that might assist you

Please read this: #9617 (comment)

[sbidoul]

Side note: we apparently don't do much with "scheme.headers" except passing them to the legacy setup.py install command ? Does that mean there are user expectations around that and we should take care of it when deprecating the setup.py install code path ?

[thanapol199717]

Hi everyone, I run into a problem on my Raspberry Pi, I don't know how to fix it. I have hope that someone can help me.

[starfoxbeta]

got this while installing conda on macOS Catalina 10.15.7.

% pip3 install conda
WARNING: Value for scheme.headers does not match. Please report this to <https://github.com/pypa/pip/issues/9617>
distutils: /Library/Frameworks/Python.framework/Versions/3.8/include/python3.8/UNKNOWN
sysconfig: /Library/Frameworks/Python.framework/Versions/3.8/include/python3.8
WARNING: Additional context:
user = False
home = None
root = None
prefix = None
.....
WARNING: Value for scheme.headers does not match. Please report this to <https://github.com/pypa/pip/issues/9617>
distutils: /Library/Frameworks/Python.framework/Versions/3.8/include/python3.8/UNKNOWN
sysconfig: /Library/Frameworks/Python.framework/Versions/3.8/include/python3.8
WARNING: Additional context:
user = False
home = None
root = None
prefix = None
ERROR: pip's dependency resolver does not currently take into account all the packages that are installed. This behaviour is the source of the following dependency conflicts.
anyio 2.2.0 requires idna>=2.8, but you have idna 2.7 which is incompatible.
Successfully installed conda-4.3.16 idna-2.7 pycosat-0.6.3 ruamel.yaml-0.17.4 ruamel.yaml.clib-0.2.2

[ihebJl]

On windows using 3.9.4 python, when importing the module later it gives error

[pradyunsg]

Please see #9617.