If your system is C based, tup [0] fulfills your request by watching the outputs of the specified commands. It isn't, however, appropriate for systems like java

If your system is C based, tup [0] fulfills your request by watching the outputs of the specified commands. It isn't, however, appropriate for systems like java that create intermediate files that the developer didn't write [1]. [0] https://gittup.org/tup/ex_a_first_tupfile.html https://gittup.org/tup/ex_a_first_tupfile.html [1] https://github.com/gittup/tup/issues/113 https://github.com/gittup/tup/issues/113 Back to bazel, I am of the impression that some of its complexity comes from a requirement to handle heterogeneous build systems. For example, some python development requires resolving both python dependencies and C. Being good at either is a bunch of work; but, handling both means rolling your own polyglot system or coordinating both as a second class citizen.