[ndmitchell]

Thanks for the comments! There are two levels at which you could make Buck2/Bazel compatible:

* At the BUILD/BUCK file level. I imagine you can get close, but there are details between each other that will be hard to overcome. Buck2 doesn't have the WORKSPACE concept, so that will be hard to emulate. Bazel doesn't have dynamic dependencies which means that things like OCaml are written as multiple rules for a single library, while Buck2 just has a single rule. I think it should be possible to define a macro layer that was common enough so that it could be implemented by both Bazel and Buck2, and then open source users could just support the unified Bazck build system. * At the rules level. These might be harder, as the subtle details tend to be quite important. Things like tsets vs depsets is likely to be an issue, as they are approximately the same mechanism, but one wired into the dependency graph and one not, which is going to show up everywhere.