Currently https://input-output-hk.github.io/haskell.nix/user-guide/ is phrased with `nix-tools` already installed, and links to https://github.com/input-output-hk/nix-tools. There, installation is recommended via ``` nix-build -A nix-tools-all-execs ``` but the README at https://github.com/input-output-hk/haskell.nix recommends ``` nix build -f https://github.com/input-output-hk/haskell.nix/archive/master.tar.gz nix-tools -o nt ``` It is unclear if there is a difference, and when to best use which, so ideally https://input-output-hk.github.io/haskell.nix/user-guide/#user-guide would just give canonical instructions.