Incompatibility with pypy3

[ob-stripe]

Issue description

Recent versions of pipenv no longer work with pypy3.

Expected result

Expected pipenv to work.

Actual result

❯ PYENV_VERSION=pypy3.5-6.0.0 pyenv exec pipenv --verbose
Traceback (most recent call last):
  File "/Users/ob/.pyenv/versions/pypy3.5-6.0.0/bin/pipenv", line 7, in <module>
    from pipenv import cli
  File "/Users/ob/.pyenv/versions/pypy3.5-6.0.0/site-packages/pipenv/__init__.py", line 47, in <module>
    from .cli import cli
  File "/Users/ob/.pyenv/versions/pypy3.5-6.0.0/site-packages/pipenv/cli/__init__.py", line 3, in <module>
    from .command import cli
  File "/Users/ob/.pyenv/versions/pypy3.5-6.0.0/site-packages/pipenv/cli/command.py", line 19, in <module>
    from .options import (
  File "/Users/ob/.pyenv/versions/pypy3.5-6.0.0/site-packages/pipenv/cli/options.py", line 11, in <module>
    from .. import environments
  File "/Users/ob/.pyenv/versions/pypy3.5-6.0.0/site-packages/pipenv/environments.py", line 7, in <module>
    from ._compat import fix_utf8
  File "/Users/ob/.pyenv/versions/pypy3.5-6.0.0/site-packages/pipenv/_compat.py", line 98, in <module>
    OUT_ENCODING, ERR_ENCODING = force_encoding()
  File "/Users/ob/.pyenv/versions/pypy3.5-6.0.0/site-packages/pipenv/_compat.py", line 68, in force_encoding
    from ctypes import pythonapi, py_object, c_char_p
ImportError: cannot import name 'pythonapi'

Steps to replicate

Simply install pipenv with PyPy3, then try to run any pipenv command.

---

pipenv --support won't work either.

PyPy doesn't support ctypes.pythonapi, but the root cause of the issue is that it shouldn't even try to import this module in the first place. I've investigated a bit and it looks with PyPy3, sys.stdout.encoding returns "utf8" instead of "utf-8". I'm unsure whether this is a PyPy bug or not, but since pipenv used to work fine with PyPy3 prior to (I think) #3096, can we relax the condition on this line to allow for "utf8" as well as "utf-8"?

[frostming]

Pipenv is not guaranteed to work on PyPy, nor is PyPy included in our CI setup.

Well, PyPy appears in setup.py classifiers? That should be removed, sorry for the trouble.

[ob-stripe]

Hey @frostming, thanks for the reply. It's a bit disappointing to hear that PyPy isn't officially supported, as it means that packages that do support PyPy need to introduce additional complexity to use pipenv only on supported Python versions or not use pipenv at all.

Also, regarding the exact issue I described, I suspect this is a bug in pipenv:

1. In __init__.py, sys.stdout and sys.stderr are replaced by io.TextIOWrappers with encoding set to 'utf8' (no dash):

   pipenv/pipenv/__init__.py

   Lines 31 to 36 in d9ebad3

   	stdout_wrapper = io.TextIOWrapper(sys.stdout.buffer, encoding='utf8')
   	atexit.register(stdout_wrapper.close)
   	stderr_wrapper = io.TextIOWrapper(sys.stderr.buffer, encoding='utf8')
   	atexit.register(stderr_wrapper.close)
   	sys.stdout = stdout_wrapper
   	sys.stderr = stderr_wrapper

2. In _compat.py, the encoding is forced to UTF-8 by checking if sys.stdout/err.encoding.lower() is equal to 'utf-8' (with a dash):

   pipenv/pipenv/_compat.py

   Line 331 in d9ebad3

   if stdout_encoding.lower() != "utf-8" or stderr_encoding.lower() != "utf-8":

[frostming]

Good catch, would like to send a PR for it?

[ob-stripe]

Certainly :) Will send one in a moment!

[ob-stripe]

PR submitted: #3322

[techalchemy]

I have no real qualms fixing PyPy support as it shouldn’t be hard...

[ywliu]

I was caught off guard with this bug with Pypy3 too. This doesn't trigger any error with Cpython as it has a module ctype to import.

Glad to know this has been fixed !

[t3hmrman]

Just noting that I just ran into this in Circle CI -- Since the #3322 PR hasn't landed in a release yet I'm going to attempt to use pipenv from master for the time being.