Others have said similar things, so my point is mostly one of emphasis. Bazel goes deep on finding edges in the build graph. Example: C/C++ has this preprocess

Others have said similar things, so my point is mostly one of emphasis. Bazel goes deep on finding edges in the build graph. Example: C/C++ has this preprocessor step where ‘#include’ and stuff happen. It’s very cheap compared to what comes next. If you change white space or comments or whatever, the preprocessor runs, hashes the same, now the .o is good, now the link is good. OP’s stuff is cool, but just wanted to make sure everyone is clear that industrial strength build systems like Bazel take on that constant factor intentionally. They are designed for building big, complex, polyglot code bases.