Nix is a package manager that you can install in parallel with your system package manager on Linux or MacOS. It allows you to effortlesly build any of the thousands of packages defined in the nixpkgs repository or write your own package expressions. Packages in the nixpkgs repository get periodically built by our CI server so the GIMP dependencies will be obtained from binary cache saving you time.
To obtain Nix, you can simply run an installation script, or use your package manager if it is packaged in your distro repositories. Notably, there is a package in Arch’s AUR and Debian Unstable.
The pull request containing changes for the latest changes for GIMP master is https://github.com/NixOS/nixpkgs/pull/67576. I usually update the branch several times a month to point to t