tests/readlink.py

packaging: add docutils as dependency

The previous commit revealed that attempting to run
`python setup.py build_doc` from the packaging virtualenv
failed due to missing docutils package. We didn't notice
this before because py2exe Windows packaging appears to
use a Python from another virtualenv (which does include
docutils) to invoke setup.py. I discovered this as part
of implementing packaging outside of that virtualenv
environment.

Differential Revision: https://phab.mercurial-scm.org/D8470

#!/usr/bin/env python

from __future__ import absolute_import, print_function

import errno
import os
import sys

for f in sys.argv[1:]:
    try:
        print(f, '->', os.readlink(f))
    except OSError as err:
        if err.errno != errno.EINVAL:
            raise
        print(f, '->', f, 'not a symlink')

sys.exit(0)