#!/usr/bin/env nix-shell
#! nix-shell -i sh -p nix-prefetch-git jq

url="https://github.com/NixOS/nixpkgs-channels/"
ref="refs/heads/nixos-19.09"

nix-prefetch-git --rev "$ref" --no-deepClone "$url" | jq --arg ref "$ref" '{ref: $ref} + .' > channel.json