this derivation will be built:
  /nix/store/zj2gngsywf7m5520wxaarr6r8rpplb5r-gastown-1.2.1.drv
this path will be fetched (560.3 KiB download, 1.3 MiB unpacked):
  /nix/store/1kz45x8bqycd4qj2ljdfpp1wqa0rcp07-tmux-3.7c