this derivation will be built:
  /nix/store/b6njpdralbanhpv1fq1w6asqfx1xrywa-keen4.drv
these 2 paths will be fetched (888.4 KiB download, 3.3 MiB unpacked):
  /nix/store/2g2zl5bqn8nv7nkh7lwpghczrw9na0d8-SDL_compat-1.2.60
  /nix/store/6n8lw053pzdcdnmz12plhzccpl5m2xrw-dosbox-0.74-3