def warn_about_missing_assertion(mode):
    try:
        assert False
    except __HOLE__:
        pass
    else:
        if mode == "rewrite":
            specifically = ("assertions which are not in test modules "
                            "will be ignored")
        else:
            specifically = "failing tests may report as passing"

        sys.stderr.write("WARNING: " + specifically +
                         " because assert statements are not executed "
                         "by the underlying Python interpreter "
                         "(are you using python -O?)\n")


# Expose this plugin's implementation for the pytest_assertrepr_compare hook
dataset/ETHPy150Open pytest-dev/pytest/_pytest/assertion/__init__.py/warn_about_missing_assertion