> Using an older Nixpkgs checkout might have a higher rate of success but if Nixpkgs never included the version you need in the first place that also doesn't wo

> Using an older Nixpkgs checkout might have a higher rate of success but if Nixpkgs never included the version you need in the first place that also doesn't work. Then you could get the package from a fork of nixpkgs where it is present.