                     distutils command which produced that file, e.g.
                        ``sdist`` or ``bdist_wheel``.
        :param pyversion: The version of Python which the release relates
                          to. For code compatible with any Python, this would
                          be ``source``, otherwise it would be e.g. ``3.2``.
        :param keystore: The path to a directory which contains the keys
                         used in signing. If not specified, the instance's
                         ``gpg_home`` attribute is used instead.
        :return: The HTTP response received from PyPI upon submission of the
                request.
        z
not found: %sNz)no signing program available - not signed