I need the with
feature which was introduced in Dhall 1.31.0. The Dhall version in Nixpkgs unstable is 1.30.0 though. I tried installing it for a Nix shell with the following where the sources point at the most recent Dhall
let
sources = import ./nix/sources.nix;
pkgs = import sources.nixpkgs {};
dhall-json = builtins.fetchTarball {
url = sources.dhall-haskell.url;
sha256 = sources.dhall-haskell.sha256;
};
foo = import "${dhall-json}";
in
pkgs.mkShell {
buildInputs = [
foo.dhall-json
];
}
The problem is that this seems to rebuild the entire world.
Is there some easy but still Nix-y way of installing the most recent Dhall version without having to recompile everything?