Nix[0] does this, sort of. It doesn't merge everything into one tree at runtime, but instead builds every package to a unique path, which gets embedded into dow

Nix[0] does this, sort of. It doesn't merge everything into one tree at runtime, but instead builds every package to a unique path, which gets embedded into downstream dependees. It assembles the dependency tree into a DAG, and uses this to automatically parallelize builds (where safe). Builds automatically run in ephemeral containers, to ensure that all dependencies are accounted for. There are also importers for many languages, and an exporter for Docker images (where each Nix package becomes one Docker layer, up until a limit that you specify). [0]: https://nixos.org/nix/ https://nixos.org/nix/