python subprocess invocation to inject setuptools pollutes setuptools argument list

setuptools (and probably distutils) assume the very first argument from sys.argv to be the executed setup file. Invoking a python subprocess with -c to execute a command will set ‘-c’ to be the very first argument to sys.argv (see the docs). This leads to the manifest_maker warning noted at https://github.com/pypa/pip/blob/9b11ed231cc0c7a8101f1ffbdc8b352a12c511b7/pip/req/req_install.py#L868 and also will cause arguments to the setuptools (or distutils) commands to be polluted with an additional ‘-c’, whether it’s wanted or not.

As a workaround, manipulate the argument list prior to exec() in https://github.com/pypa/pip/blob/9b11ed231cc0c7a8101f1ffbdc8b352a12c511b7/pip/req/req_install.py#L843 and similar invocations within pip:

import sys, setuptools, tokenize
sys.argv[0] = %r; ....

[koobs]

Happy 5 year birthday for this issue (last month)! Thank you for resolving this @cjerdonek 😃

FWIW, the review/diff URL mentioned in my earlier comment is now https://reviews.freebsd.org/D270

[koobs]

@cjerdonek I think the best way to answer that question is wherever the issue is found/reproducible, which at the time of the report, was distutils, setuptools, pip.

I looked through @marcusva’s history around the time this issue was created and couldn’t see a referenced setuptools bug report