The file packages.bzl in this directory lists all packages available in the chosen Stackage snapshot.

To update the Stackage snapshot you need to clone the hazel repository into a separate directory:

$ git clone https://github.com/FormationAI/hazel.git

Change into the hazel repository root directory.

$ cd hazel

Then execute the following command to update to the specified Stackage snapshot, where $PROJECT points to the root of this repository: (Requires stack)

$ Stackage.hs lts-12.4 "$PROJECT/hazel/packages.bzl"

On NixOS you may need to modify Stackage.hs to append the following flag to the list of stack intrepreter flags: --nix-packages zlib.

This will take a while.