Fair enough, I stand corrected. Superficially it seems like a more pleasant experience than dealing with gn/ninja as an end user.
https://github.com/apple/foundationdb/blob/master/Makefile#L...
And then there were the hijinks we went through to build a cross-compiler with modern gcc and ancient libc (plus the steps to make sure no dependency on later glibc symbols snuck in):
https://github.com/apple/foundationdb/blob/master/build/link...
Ahh... now that was a build system.
(with apologies to Tolkien)