setup.cfg options package_dir
package_dir dict
https://setuptools.pypa.io/en/latest/userguide/commands.html#other-egg-info-options
setup.py egg_info --egg-base
This should normally be the root of your project’s source tree
some projects use a src or lib subdirectory as the source root
as it is normally determined from the package_dir argument to the setup() function, if any.