Getting started with Hix

Hix is a command line tool that provides an easy way to add haskell.nix support to existing haskell projects.

You will need nix installed and in you PATH with nix in PATH with experimental-features = [ "nix-command" "flakes" ]; configured. See for details.

Using hix init and nix

The hix init command adds a flake.nix and nix/hix.nix file. After that the project can be used with regular nix tools.

For instance to run cabal build on the hello package from hackage:

cabal unpack hello
cd hello-
nix run "github:input-output-hk/haskell.nix#hix" -- init
nix develop
cabal build

To view the contents of the flake run:

nix flake show

To build a component with nix:

nix build .#hello:exe:hello

To build and run a component:

nix run .#hello:exe:hello

Installing Hix

To use the other Hix features first install Hix with:

nix-env -iA hix -f

To update run to the latest version run:

hix update

Using hix develop, hix flake, hix build and hix run

These commands work the same as the nix versions without using the flake.nix. Instead a boiler plate haskell.nix flake.nix file is added to .hix-flake/flake.nix and used from there.

The is can be useful if the project already includes a flake.nix or if you do not intend to maintain one.

Then all of these should work without the need to run hix init:

hix develop
hix flake show
hix build .#hello:exe:hello
hix run .#hello:exe:hello

Using hix-shell and hix-build

These commands behave like nix-build and hix-shell would if a boiler plate default.nix and shell.nix we present.

hix-shell --run 'cabal build all'
hix-build -A hsPkgs.hello.components.exes.hello