How about this? 1. You update a copy of a repo which defines all inputs in a repeatable way (all inputs are either part of the repo or their hashes are verifie

How about this? 1. You update a copy of a repo which defines all inputs in a repeatable way (all inputs are either part of the repo or their hashes are verified during build). Nix does this. 2. You upload the build outputs to a publicly available cache server, like Cachix. 3. You send the changes to someone else for inclusion in their repo. 4. They verify that your code doesn't do anything that looks like sandbox breaking, and that at least all the original tests are still in place. Or they have their own way to keep the run sandboxed and to test coverage. 5. They run the code (pointing at the cache server), which should reuse the cached results and finish almost immediately.