[ndmitchell]

I think of Shake as a library for implementing build systems, and was hoping that libraries would emerge that described how to implement rules like C++, and how they should compose together so you can compile C++/Haskell/Python all together happily. A few libraries emerged, but the overall design never emerged. Sorry you got burned :(

Buck2 is at a higher level than Shake - the rules/providers concepts pretty much force you into a pattern of composable rules. The fact that Meta has lots of languages, and that we were able to release those rules, hopefully means it's starting from the point of view of a working ecosystem. Writing those rules took a phenomenal amount of effort from a huge range of experts, so perhaps it was naive that Shake could ever get there on only open source volunteer effort.