Activate the subprocess compatibility.

def fix_subprocess(override_debug=False, override_exception=False):
    """Activate the subprocess compatibility."""
    import subprocess

    # Exceptions
    if subprocess.__dict__.get("SubprocessError") is None:
        subprocess.SubprocessError = _Internal.SubprocessError
    if _InternalReferences.UsedCalledProcessError is None:
        if "CalledProcessError" in subprocess.__dict__:
            _subprocess_called_process_error(True, subprocess)
        else:
            _subprocess_called_process_error(False, subprocess)
            subprocess.CalledProcessError = _InternalReferences.UsedCalledProcessError

    def _check_output(*args, **kwargs):
        if "stdout" in kwargs:
            raise ValueError("stdout argument not allowed, "
                             "it will be overridden.")
        process = subprocess.Popen(stdout=subprocess.PIPE, *args, **kwargs)
        stdout_data, __ = process.communicate()
        ret_code = process.poll()
        if ret_code is None:
            raise RuntimeWarning("The process is not yet terminated.")
        if ret_code:
            cmd = kwargs.get("args")
            if cmd is None:
                cmd = args[0]
            raise _InternalReferences.UsedCalledProcessError(returncode=ret_code, cmd=cmd, output=stdout_data)
        return stdout_data

    try:
        subprocess.check_output
    except AttributeError:
        subprocess.check_output = _check_output