AttributeError: 'FakePipeWrapper' object has no attribute 'delete_on_close'

[ghost]

Describe the bug
When using plumbum and the fake filesystem I'm unable to run plumbum commands (which uses Popen).

Note you can test what do_something's behavior should be by doing a:

Patricks-MacBook-Pro-2:bugs pburton$ python3
Python 3.7.3 (default, Mar 27 2019, 09:23:15) 
[Clang 10.0.1 (clang-1001.0.46.3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from test_plumbum import do_something
>>> do_something()
hello world!

>>> 

How To Reproduce

requirements.txt:

plumbum
pytest
pyfakefs

test_plumbum.py contents:

import pytest

from plumbum.cmd import echo


def do_something():
    e_hello_world = echo["hello world!"]
    print(e_hello_world())


def test_do_something(fs):
    do_something()

Run python3 -m "pytest" test_plumbum.py and you will see the following output:

test_plumbumbug.py F                                                                                                                                                                          [100%]

============================================================================================= FAILURES ==============================================================================================
_________________________________________________________________________________________ test_do_something _________________________________________________________________________________________

fs = <pyfakefs.fake_filesystem.FakeFilesystem object at 0x1114fd128>

    def test_do_something(fs):
>       do_something()

/Users/pburton/bugs/test_plumbumbug.py:12: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
/Users/pburton/bugs/test_plumbumbug.py:8: in do_something
    e_hello_world()
/usr/local/lib/python3.7/site-packages/plumbum/commands/base.py:103: in __call__
    return self.run(args, **kwargs)[1]
/usr/local/lib/python3.7/site-packages/plumbum/commands/base.py:239: in run
    with self.bgrun(args, **kwargs) as p:
/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/contextlib.py:112: in __enter__
    return next(self.gen)
/usr/local/lib/python3.7/site-packages/plumbum/commands/base.py:193: in bgrun
    p = self.popen(args, **kwargs)
/usr/local/lib/python3.7/site-packages/plumbum/commands/base.py:320: in popen
    return self.cmd.popen(self.args + list(args), **kwargs)
/usr/local/lib/python3.7/site-packages/plumbum/machines/local.py:125: in popen
    **kwargs)
/usr/local/lib/python3.7/site-packages/plumbum/machines/local.py:305: in _popen
    **kwargs)  # bufsize = 4096
/usr/local/lib/python3.7/site-packages/plumbum/machines/local.py:40: in __init__
    self._proc = Popen(*args, **kwargs)
/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/subprocess.py:753: in __init__
    self.stdin = io.open(p2cwrite, 'wb', bufsize)
/usr/local/lib/python3.7/site-packages/pyfakefs/fake_filesystem.py:4640: in open
    newline, closefd, opener)
/usr/local/lib/python3.7/site-packages/pyfakefs/fake_filesystem.py:5168: in __call__
    return self.call(*args, **kwargs)
/usr/local/lib/python3.7/site-packages/pyfakefs/fake_filesystem.py:5216: in call
    file_)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <pyfakefs.fake_filesystem.FakeFileOpen object at 0x1110650f0>, file_ = 4

    def _handle_file_arg(self, file_):
        file_object = None
        if isinstance(file_, int):
            # opening a file descriptor
            filedes = file_
            wrapper = self.filesystem.get_open_file(filedes)
>           self._delete_on_close = wrapper.delete_on_close
E           AttributeError: 'FakePipeWrapper' object has no attribute 'delete_on_close'

/usr/local/lib/python3.7/site-packages/pyfakefs/fake_filesystem.py:5297: AttributeError

Your enviroment
Please run the following and paste the output.

python3 -c "import platform; print(platform.platform())"
Darwin-18.6.0-x86_64-i386-64bit
python3 -c "import sys; print('Python', sys.version)"
Python 3.7.3 (default, Mar 27 2019, 09:23:15) 
[Clang 10.0.1 (clang-1001.0.46.3)]
python3 -c "from pyfakefs.fake_filesystem import __version__; print('pyfakefs', __version__)"
pyfakefs 3.6

[mrbean-bremen]

Thanks for the report!
While this concrete exception is probaly easy to fix (and we will certainly do that), I doubt that your example will work anyway as it uses subprocess, which internally uses C calls to access the file system.
You may also check the similar issues #187 and #447.