rust-cpython: switch logging facade from `simple_logger` to `env_logger`
`simple_logger` is just too simple. `env_logger` supports logging to `stderr`,
and logging filtering, for example, which are becoming necessary now. The
project is nicely active.
Differential Revision: https://phab.mercurial-scm.org/D8990
#!/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)