I would say that is somewhat outside the jurisdiction of the VCS. Sure you can have post-commit or CI hooks that ensure your code always compiles, but it doesn'

I would say that is somewhat outside the jurisdiction of the VCS. Sure you can have post-commit or CI hooks that ensure your code always compiles, but it doesn't need deep support from the VCS to do that. However, the fact the pijul doesn't really treat the "no conflict" state as "special" is in some ways closer to what you want - the repo is just a collection of patches, and whether the result is "good" or "bad" is not determined by the VCS, but by whatever means you choose to employ.