> For example, OpenBSD at some point changed how mmap() was defined so that it takes seven arguments:
It seems like that was the case from day one, when a copy of the NetBSD code was imported to later become OpenBSD[1]. And if my reasoning is correct, saying that OpenBSD “changed it at some point” is not quite correct.
https://github.com/openbsd/src/blob/df930be708d50e9715f173ca...