Setuptools was imported prior to invocation, so it is
    unsafe to unload it. Bail out.

def _conflict_bail(VC_err, version):
    """
    Setuptools was imported prior to invocation, so it is
    unsafe to unload it. Bail out.
    """
    conflict_tmpl = textwrap.dedent("""
        The required version of setuptools (>={version}) is not available,
        and can't be installed while this script is running. Please
        install a more recent version first, using
        'easy_install -U setuptools'.

        (Currently using {VC_err.args[0]!r})
        """)
    msg = conflict_tmpl.format(**locals())
    sys.stderr.write(msg)
    sys.exit(2)