Issue
The problem is here. When one or more extra search dir is specified, the resulting command looks like this [<python>, '-m', 'pip', '-q', 'install', '--only-binary', ':all:', '--no-index', 'pip', 'setuptools', 'wheel', '--find-links', '/usr/lib/python3.8/site-packages/virtualenv/seed/embed/wheels', [extra dir one], [extra dir two]]. Which leads to pip tries to install [extra dir one] as a package and error message: ERROR: Directory '[extra dir one]' is not installable. Neither 'setup.py' nor 'pyproject.toml' found.
pip needs to have each directory specified with --find-links so the command should look like this: [<python>, '-m', 'pip', '-q', 'install', '--only-binary', ':all:', '--no-index', 'pip', 'setuptools', 'wheel', '--find-links', '/usr/lib/python3.8/site-packages/virtualenv/seed/embed/wheels', '--find-links', [extra dir one], '--find-links', [extra dir two]].
I'll open a PR for this.
Issue
The problem is here. When one or more extra search dir is specified, the resulting command looks like this
[<python>, '-m', 'pip', '-q', 'install', '--only-binary', ':all:', '--no-index', 'pip', 'setuptools', 'wheel', '--find-links', '/usr/lib/python3.8/site-packages/virtualenv/seed/embed/wheels', [extra dir one], [extra dir two]]. Which leads to pip tries to install[extra dir one]as a package and error message:ERROR: Directory '[extra dir one]' is not installable. Neither 'setup.py' nor 'pyproject.toml' found.pip needs to have each directory specified with
--find-linksso the command should look like this:[<python>, '-m', 'pip', '-q', 'install', '--only-binary', ':all:', '--no-index', 'pip', 'setuptools', 'wheel', '--find-links', '/usr/lib/python3.8/site-packages/virtualenv/seed/embed/wheels', '--find-links', [extra dir one], '--find-links', [extra dir two]].I'll open a PR for this.