def check_simulation(wdir):
    """
    Check bhdebug.txt to make sure that you specify enough digits to
    overcome roundoff errors.
    """
    wdir = pathlib.Path(wdir)
    field = wdir / "V_0Ereim.dat"
    if not (field.exists() and
            field.stat().st_size > 130):
        msg = "Output {} does not exist or is too small!".format(field)
        raise BHFIELDExecutionError(msg)