I love fabricate---even helped with the OSX port. I had to give up on it when El Cap came out; I just didn't have time to work around SIP. The other problem with fabricate/tup/not-Make is they store the structure of the dependency graph. This leads to ugly build ... worries when you have subtle dependency changes caused by, e.g., updates to system headers, or interactions in large rule-bases. I just never had confidence the builds were correct.

However, using Make + ccache + a custom ar wrapper (port the deterministic flags from Linux to BSD), I got all the speed up of tup/fabricate, using off-the-shelf open source tooling. I've never looked back.