Unfortunately it's not so easy to upgrade the system's Python, however, it is something we might try.  The reproducing test case would appear to be akin to:

"import _socket"

And, within the gevent stack trace program, https://github.com/schmir/gevent/blob/master/gevent/monkey.py#L109

But to be precise, it is stuck at: https://github.com/heroku/WAL-E/blob/master/wal_e/cmd.py#L17.  None of this is very helpful, I realize, but this program (in this case, when archiving PostgreSQL write-ahead-log archives) is started up millions of times in a day, putting the defect rate at not far from the nominally figurative phrase "one in a million".