Binary path of python installed by pyenv is not properly got in some cases

[jxltom]

Pyenv will install python to ~/.pyenv/versions/some_version/bin. The binary directory is got by

pythonfinder/src/pythonfinder/models/pyenv.py

Line 74 in 2b0530a

bin_ = sysconfig._INSTALL_SCHEMES[sysconfig._get_default_scheme()]["scripts"]

.

Normally, sysconfig._get_default_scheme() will return {base}/bin which then help us getting the right pyenv python location.

However, in my local ubuntu 16.04 (probably it is because I'm using system built-in python version) and also in windows subsystem for linux, sysconfig._get_default_scheme() returns {base}/local/bin which makes getting pyenv python location as ~/.pyenv/versions/some_version/local/bin. This path does not exist apparently.

This make latest pipenv can not find the pyenv python version and raise following error.

➜  test pipenv --python 3.6.3
Traceback (most recent call last):
  File "/usr/local/bin/pipenv", line 11, in <module>
    load_entry_point('pipenv', 'console_scripts', 'pipenv')()
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/click/core.py", line 764, in __call__
    return self.main(*args, **kwargs)
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/click/core.py", line 717, in main
    rv = self.invoke(ctx)
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/click/core.py", line 1114, in invoke
    return Command.invoke(self, ctx)
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/click/core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/click/decorators.py", line 64, in new_func
    return ctx.invoke(f, obj, *args, **kwargs)
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/click/decorators.py", line 17, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/home/user/Documents/dev/pipenv/pipenv/cli/command.py", line 203, in cli
    clear=state.clear,
  File "/home/user/Documents/dev/pipenv/pipenv/core.py", line 595, in ensure_project
    pypi_mirror=pypi_mirror,
  File "/home/user/Documents/dev/pipenv/pipenv/core.py", line 537, in ensure_virtualenv
    ensure_python(three=three, python=python)
  File "/home/user/Documents/dev/pipenv/pipenv/core.py", line 421, in ensure_python
    path_to_python = find_a_system_python(python)
  File "/home/user/Documents/dev/pipenv/pipenv/core.py", line 384, in find_a_system_python
    python_entry = finder.find_python_version(line)
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/backports/functools_lru_cache.py", line 137, in wrapper
    result = user_function(*args, **kwds)
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/pythonfinder/pythonfinder.py", line 112, in find_python_version
    return self.system_path.find_python_version(
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/pythonfinder/pythonfinder.py", line 53, in system_path
    ignore_unsupported=self.ignore_unsupported,
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/pythonfinder/models/path.py", line 395, in create
    ignore_unsupported=ignore_unsupported,
  File "<attrs generated init 8b5e681b06af133646fcafad5a215f2a935c5776>", line 37, in __init__
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/pythonfinder/models/path.py", line 107, in __attrs_post_init__
    self._setup_pyenv()
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/pythonfinder/models/path.py", line 139, in _setup_pyenv
    root=PYENV_ROOT, ignore_unsupported=self.ignore_unsupported
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/pythonfinder/models/pyenv.py", line 128, in create
    return cls(root=root, ignore_unsupported=ignore_unsupported)
  File "<attrs generated init ad2b651619e57cf5a5c544e22e7f046f4487c68e>", line 19, in __init__
  File "/home/user/Documents/dev/pipenv/pipenv/vendor/pythonfinder/models/pyenv.py", line 122, in get_pythons
    pythons.update(p.pythons)
AttributeError: 'NoneType' object has no attribute 'pythons'

How about let's pin the _get_default_scheme to posix_prefix?