Kindly refer https://github.com/sympy/sympy/blob/master/sympy/core/numbers.py#L1207
In the initial commit, I had *wrongly* modified `Rational.__rmod__` when I should have modified `Rational.__mod__`.
So, I just corrected that mistake by changing `Rational.__rmod__` to what it was previously.
Btw, tests are running fine on my system [ for `sympy.test('_numbers')`].

    "I think this is the source of the test failure."
- Which test is that?

Thanks