You're basically describing Nix.

The big issue I see with Nix is that it's solving several related & very complex problems, and isn't doing so at a particularly easy level of abstraction. It's a PITA to package software that isn't using an already-supported build system. And mixing versions is messy, instead of just `[ package1="versionA", package2="versionB", …]` sort of thing with a lockfile to convert versions to immutable IDs like commit hashes you have to specify which commits of nixpkgs had each version and then do something like `nixpkgs-versionA=GIT_COMMIT_HASH_A; nixpkgs-versionB=GIT_COMMIT_HASH_B; [ nixpkgs-versionA.package1, nixpkgs-versionB.package2, …]`. There are lots of other "warts" like that, of varying levels of annoyance.