Nix Overrides That Expire Themselves

I recently published yesod-form-1.7.10 to Hackage. My project gets all of its dependencies from nixpkgs, and nixpkgs gradually adopts Haskell packages from Hackage. That means that there’s some time between when the package lands in nixpkgs, and when I need to use the package in my project, which is right now. You can write an override in your flake.nix to get the newer package you need, but what…