haskell.nix/docs/dev/installing-nix-tools.md

Installing nix-tools

To build the latest nix-tools and store the result at ./nt, run:

nix build -f https://github.com/input-output-hk/haskell.nix/archive/master.tar.gz pkgs.haskell-nix.nix-tools.ghc884 --out-link nt

If you would like to then install nix-tools into your profile, run:

nix-env -i ./nt

Optional: Installing via Haskell.nix source

The Haskell.nix and nix-tools source will be useful if you would like to contribute improvements, or read the source code to fully understand something that the documentation doesn't cover.

git clone https://github.com/input-output-hk/nix-tools
git clone https://github.com/input-output-hk/haskell.nix
cd haskell.nix
nix build -f . pkgs.haskell-nix.nix-tools.ghc884 --arg sourcesOverride '{ nix-tools = ../nix-tools; }' --out-link nt