FTP tests fail on Pypy

[willmcgugan]

FTPFS tests fail on Pypy. We should fix that and add Pypy builds to Travis.

[chfw]

here is the travis snippet that you need:

python:
  - &pypy2 pypy2.7-6.0
  - &pypy3 pypy3.5-6.0

reference:

https://github.com/moremoban/pypi-mobans/blob/dev/templates/travis.yml.jj2

example build: https://travis-ci.org/pyexcel/pyexcel

[dargueta]

Was there a bug introduced in PyPy 7.x? Pinning it to 6.x seems like a bit of a hack.

Update:

PyPy2 and PyPy3 are failing for two different reasons, but both still in ftpfs.py:

• PyPy2.7 (7.1.1): Unable to connect to FTP server
• PyPy3.5 (5.10.1): GeneratorExit ignored in _scandir(), possibly a red herring triggered by this (cannot release un-acquired lock).

Note the version number discrepancy. I think we're dealing with two separate problems here.

Update 2:

The PyPy3.5 crash is caused by this bug and was fixed in 7.0.0. This leaves us with the PyPy2 bug to figure out.

[dargueta]

Considering Python 2 has been EOL for months now I think we can ignore the PyPy 2 CI failures and close this ticket.