by-license.sh

json=$(nix eval --json '(
  with builtins;
  with import <nixpkgs/nixos> { };
  with pkgs.lib;
  let try = x: default: let res = tryEval x; in if res.success then res.value else default; in
  groupBy
    (x: x.meta.license.shortName)
    (concatMap (pkg:
      try (
        let x = map (pkg: { inherit (pkg) name; meta = { inherit (pkg.meta) license; }; })
          (filter (pkg: pkg.meta ? license && pkg.meta.license ? shortName) [ pkg ]);
        in deepSeq x x) []
    ) config.environment.systemPackages)
)') && jq '.' <<< "$json" > packages.json