Drift: Update Nix Flake package sources

I’ve wanted support for update scripts in Flakes like NixPkgs has for a while and finally got around to hacking on this. With Drift, you can now create and run update scripts for your packages. This includes the ability to run arbitrary commands and comes with a quick helper for updating the version and hash of your package’s source. Drift also supports updating the package source’s hash to match the version automatically.

Give it a try and let me know what you think!