Thank You for all Your advice.

As modifying standard modules is risky - especially if you update and forget your changes - I tried a brute force method for testing and succeeded. I simply installed the module despite the error, ran my tests and scripts and they worked.

Well, I know that the this does not prove *all* cases and the absence of future problems, but it helps for the moment. Tye, I keep Your advice for $! in mind, that might help me survive if needed.