Hello Guix, I am hacking on the build scripts of an existing project and need to make sure that my changes do not affect the actual build products. Is there a good way to leverage guix for this? Previously, I had been doing this manually by (deterministically) tarring up the build products and comparing hashes; however, this is a bit prone to me flubbing up the tar-hash-compare process. For a brief moment, I thought I could write a package definition that points to a specific `devel/foo' branch of my repo and then have `guix build --check` compare builds as I update the branch head. However, the source hash obviously changes, so this idea is dead in the water. What I need is a way to verify whether build outputs change as I make on the `devel/foo' branch. Any brilliant ideas? Cheers!