these 3 derivations will be built:
  /nix/store/1r180rc2zwsrkmr01qh9q1x684mgqz3z-treefmt.toml.drv
  /nix/store/f59bdaw599kyrzxrgpw4cdj1gq11mrid-treefmt.drv
  /nix/store/1r60q4pm6lxrnsb3490gnw0rarb9f7sn-treefmt-check.drv
this path will be fetched (5.9 MiB download, 18.0 MiB unpacked):
  /nix/store/gb6lybvfzfdx7jb51vmaif4fic925mc7-rumdl-0.2.64