We did in build2[1]. Specifically, we have a notion of target type which may not be path or mtime-based. For example, one such target type is alias (something t

We did in build2[1]. Specifically, we have a notion of target type which may not be path or mtime-based. For example, one such target type is alias (something that is achieved in make with PHONY targets). So you could define, say, a url target type. Then you can implement a rule that knows how to perform a certain operation on certain target types (we've also generalized a notion of operation so in build2 test, install, dist are operations, not targets). [1] https://build2.org https://build2.org