a.rb

$ cat > setup.py              
__import__('setuptools').setup(name='foo', version='1.0', packages=__import__('setuptools').find_packages())
$ python setup.py sdist         
running sdist
running egg_info
writing foo.egg-info/PKG-INFO
writing dependency_links to foo.egg-info/dependency_links.txt
writing top-level names to foo.egg-info/top_level.txt
reading manifest file 'foo.egg-info/SOURCES.txt'
writing manifest file 'foo.egg-info/SOURCES.txt'
warning: sdist: standard file not found: should have one of README, README.rst, README.txt, README.md

running check
warning: check: missing required meta-data: url

warning: check: missing meta-data: either (author and author_email) or (maintainer and maintainer_email) must be supplied

creating foo-1.0
creating foo-1.0/cheroot
creating foo-1.0/cheroot/test
creating foo-1.0/foo.egg-info
copying files to foo-1.0...
copying setup.py -> foo-1.0
copying cheroot/__init__.py -> foo-1.0/cheroot
copying cheroot/test/__init__.py -> foo-1.0/cheroot/test
copying cheroot/test/test_core_backup.py -> foo-1.0/cheroot/test
copying foo.egg-info/PKG-INFO -> foo-1.0/foo.egg-info
copying foo.egg-info/SOURCES.txt -> foo-1.0/foo.egg-info
copying foo.egg-info/dependency_links.txt -> foo-1.0/foo.egg-info
copying foo.egg-info/top_level.txt -> foo-1.0/foo.egg-info
Writing foo-1.0/setup.cfg
Creating tar archive
removing 'foo-1.0' (and everything under it)