#!/usr/bin/env nix
#! nix shell nixpkgs#bash nixpkgs#gnugrep nixpkgs#nixVersions.latest --command bash

# diffs each derivation

set -x
set -v
set -e

if [ "$#" -ne 1 ]; then
  echo "$0 (pre|post)"
  exit 1
fi

script_path=$(dirname "$(readlink -f $0)")
parent_path=$(dirname "$script_path")
out_path="$parent_path/$1.json"

nix run . -- --evaluate --json "$out_path" "$parent_path"