How to reproduce this bug?

[IUM259]

A bug was fixed in MCHPRS, file changed: f0486c1
see line 415.
I want know how to reproduce repeater bug in a previous version of MCHPRS (i have) but dont know how to test and reproduce bug.

[commanderguy3001]

if I understand you correctly, you wanna reproduce a bug that's already been fixed? why?

[IUM259]

Yes, I don't know what the bug was. Do you know what it was? And how it was reproduced?
I want to find an alternative circuit to something that uses this bug and no longer works, and understanding this bug may help a circuit to run on vanilla MC.
I clarify that I want to reproduce the bug (to understand it) in an old version of MCHPRS (where it has not yet been solved) but for that I need to know how it was reproduced or what caused it.