I didn't submit this as a bug report but as an enhancement request. From usability point of view, saying that results differ but you just cannot see the difference is not very helpful.

The exact reason I didn't submit this as an enhancement request for unittest, pytest, and all other modules/tools being affected is that "I'm not sure if there's a good way to detect whether two unicode strings are going to display confusingly similarly". Enhancing `repr()` would be a logical solution to this problem.

Finally, would any harm be done if `repr('hyva\u0308')` would be changed to `'hyva\\u0308'`? I don't see it being any different than `repr('foo\x00')` being `'foo\\x00'`; in both cases you can `eval()` the result to get the original value back like `repr()` is supposed to do when possible. Most importantly, the result would show that the value actually contains like you generally expect `repr()` to do.