[mileswjohnson]

Our configuration is using globs but under the hood we content hash all the files that match the glob, and only run/cache if the aggregated hash has changed.

For the languages we currently support, this is more than enough. Once we dive deeper into compiled languages (probably starting with Rust), we'll look into more granular reactivity and possible use something like sccache.

[thundergolfer]

Bazel's glob does the same thing. I'm not sure what the OP means, Bazel's incrementality is aided by fine-grained build input specification, but it's incrementaility is at core a combination of deterministic build rules, storage of build rule execution history, and early-stopping.

[kccqzy]

I don't see how that solves the problem mentioned by OP. If the build rule mentions foo.c, we only need to recompile that one object and relink. When you are using globs, changing one file changes the aggregated hash and then would necessitate recompiling every object file.