I don't think there's a guide, the only resource I'm aware of is The Open Group Base Specifications[1] which can be reference when in doubt. Almost other times

I don't think there's a guide, the only resource I'm aware of is The Open Group Base Specifications[1] which can be reference when in doubt. Almost other times I just install bmake alongside with gmake and try to get it work with both (it's still not perfectly conform to POSIX, since GNU supports some of BSD's make feature, and vice versa). [1]: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/make.html https://pubs.opengroup.org/onlinepubs/9699919799/utilities/m...