Can't read from stdin using flake8-coding and flake8-print at the same time

[johnson-christopher]

Can't use flake8-coding and flake8-print at the same time for emacs flycheck. Unfortunately I don't know if flake8-print or flake8-coding is the issue, but here's the setup. Flycheck attempts to lint my file by running the following command to start flake8 and then feed the file in via stdin:

python -c "import sys,runpy;sys.path.pop(0);runpy.run_module('flake8')" --format=default - < /path/to/my/file.py

The traceback is as follows:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/local/Cellar/python/3.6.5_1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/runpy.py", line 208, in run_module
    return _run_code(code, {}, init_globals, run_name, mod_spec)
  File "/usr/local/Cellar/python/3.6.5_1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/[scrubbed]/.virtualenvs/transloc/lib/python3.6/site-packages/flake8/__main__.py", line 4, in <module>
    cli.main()
  File "/[scrubbed]/.virtualenvs/transloc/lib/python3.6/site-packages/flake8/main/cli.py", line 16, in main
    app.run(argv)
  File "/[scrubbed]/.virtualenvs/transloc/lib/python3.6/site-packages/flake8/main/application.py", line 396, in run
    self._run(argv)
  File "/[scrubbed]/.virtualenvs/transloc/lib/python3.6/site-packages/flake8/main/application.py", line 384, in _run
    self.run_checks()
  File "/[scrubbed]/.virtualenvs/transloc/lib/python3.6/site-packages/flake8/main/application.py", line 310, in run_checks
    self.file_checker_manager.run()
  File "/[scrubbed]/.virtualenvs/transloc/lib/python3.6/site-packages/flake8/checker.py", line 321, in run
    self.run_serial()
  File "/[scrubbed]/.virtualenvs/transloc/lib/python3.6/site-packages/flake8/checker.py", line 305, in run_serial
    checker.run_checks()
  File "/[scrubbed]/.virtualenvs/transloc/lib/python3.6/site-packages/flake8/checker.py", line 579, in run_checks
    self.run_ast_checks()
  File "/[scrubbed]/.virtualenvs/transloc/lib/python3.6/site-packages/flake8/checker.py", line 493, in run_ast_checks
    for (line_number, offset, text, check) in runner:
  File "/[scrubbed]/.virtualenvs/transloc/lib/python3.6/site-packages/flake8_coding.py", line 53, in run
    lines = self.read_headers()
  File "/[scrubbed]/.virtualenvs/transloc/lib/python3.6/site-packages/flake8_coding.py", line 45, in read_headers
    return pep8.stdin_get_value().splitlines(True)[:2]
  File "/[scrubbed]/.virtualenvs/transloc/lib/python3.6/site-packages/pycodestyle.py", line 1347, in stdin_get_value
    return TextIOWrapper(sys.stdin.buffer, errors='ignore').read()
ValueError: I/O operation on closed file

If I uninstall flake8-coding or flake8-print either one the problem goes away, so I don't know which one is the cause. Trying here first since flake8-coding is the one in the traceback, so I figure if nothing else it's the best place to find out why it crashed, even if it turns out flake8-print is the culprit.

Currently installed versions:

flake8==3.5.0
flake8-coding==1.3.0
flake8-print==3.1.0

[johnson-christopher]

I found a possible fix by looking at flake8-commas. It appears using flake8.engine.pep8.stdin_get_value instead of the one from pycodestyle will fix it. PR will be up soon.

[johnson-christopher]

@tk0miya Can you look at this PR when you get a chance?