# Buggy code
def cmd_output_b(
    *cmd: str,
    retcode: Optional[int] = 0,
    **kwargs: Any,
) -> Tuple[int, bytes, Optional[bytes]]:
    _setdefault_kwargs(kwargs)

    try:
        cmd = parse_shebang.normalize_cmd(cmd)
    except parse_shebang.ExecutableNotFoundError as e:
        returncode, stdout_b, stderr_b = e.to_output()
    else:
        proc = subprocess.Popen(cmd, **kwargs)
        stdout_b, stderr_b = proc.communicate()
        returncode = proc.returncode

    if retcode is not None and retcode != returncode:
        raise CalledProcessError(returncode, cmd, retcode, stdout_b, stderr_b)

    return returncode, stdout_b, stderr_b


# Traceback (OSError)
Traceback (most recent call last):
File "/[redacted]/venv/lib/python3.7/site-packages/pre_commit/error_handler.py", line 54, in error_handler
yield
File "/[redacted]/venv/lib/python3.7/site-packages/pre_commit/main.py", line 371, in main
return run(args.config, store, args)
File "/[redacted]/venv/lib/python3.7/site-packages/pre_commit/commands/run.py", line 339, in run
return _run_hooks(config, hooks, args, environ)
File "/[redacted]/venv/lib/python3.7/site-packages/pre_commit/commands/run.py", line 249, in _run_hooks
verbose=args.verbose, use_color=args.color,
File "/[redacted]/venv/lib/python3.7/site-packages/pre_commit/commands/run.py", line 165, in _run_single_hook
retcode, out = language.run_hook(hook, filenames, use_color)
File "/[redacted]/venv/lib/python3.7/site-packages/pre_commit/languages/script.py", line 19, in run_hook
return helpers.run_xargs(hook, cmd, file_args, color=color)
File "/[redacted]/venv/lib/python3.7/site-packages/pre_commit/languages/helpers.py", line 109, in run_xargs
return xargs(cmd, file_args, **kwargs)
File "/[redacted]/venv/lib/python3.7/site-packages/pre_commit/xargs.py", line 153, in xargs
for proc_retcode, proc_out, _ in results:
File "/usr/local/Cellar/python/3.7.6_1/Frameworks/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/_base.py", line 598, in result_iterator
yield fs.pop().result()
File "/usr/local/Cellar/python/3.7.6_1/Frameworks/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/_base.py", line 428, in result
return self.__get_result()
File "/usr/local/Cellar/python/3.7.6_1/Frameworks/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/_base.py", line 384, in __get_result
raise self._exception
File "/usr/local/Cellar/python/3.7.6_1/Frameworks/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/thread.py", line 57, in run
result = self.fn(*self.args, **self.kwargs)
File "/[redacted]/venv/lib/python3.7/site-packages/pre_commit/xargs.py", line 146, in run_cmd_partition
*run_cmd, retcode=None, stderr=subprocess.STDOUT, **kwargs,
File "/[redacted]/venv/lib/python3.7/site-packages/pre_commit/util.py", line 208, in cmd_output_p
proc = subprocess.Popen(cmd, **kwargs)
File "/usr/local/Cellar/python/3.7.6_1/Frameworks/Python.framework/Versions/3.7/lib/python3.7/subprocess.py", line 800, in __init__
restore_signals, start_new_session)
File "/usr/local/Cellar/python/3.7.6_1/Frameworks/Python.framework/Versions/3.7/lib/python3.7/subprocess.py", line 1551, in _execute_child
raise child_exception_type(errno_num, err_msg, err_filename)
OSError: [Errno 8] Exec format error: '/[redacted]/foo.py'

# Fixed code
def cmd_output_b(
    *cmd: str,
    retcode: Optional[int] = 0,
    **kwargs: Any,
) -> Tuple[int, bytes, Optional[bytes]]:
    _setdefault_kwargs(kwargs)

    try:
        cmd = parse_shebang.normalize_cmd(cmd)
    except parse_shebang.ExecutableNotFoundError as e:
        returncode, stdout_b, stderr_b = e.to_output()
    else:
        try:
            proc = subprocess.Popen(cmd, **kwargs)
        except OSError as e:
            returncode, stdout_b, stderr_b = _oserror_to_output(e)
        else:
            stdout_b, stderr_b = proc.communicate()
            returncode = proc.returncode

    if retcode is not None and retcode != returncode:
        raise CalledProcessError(returncode, cmd, retcode, stdout_b, stderr_b)

    return returncode, stdout_b, stderr_b