this derivation will be built:
  /nix/store/mvq1ayj2159156ksrp5wwqafjlg3d4lj-keen4.drv
these 2 paths will be fetched (953.2 KiB download, 3.6 MiB unpacked):
  /nix/store/8sk46gs0276m5rkrp7ddlnnjnjcxbrnx-SDL_compat-1.2.60
  /nix/store/mkrggw3jdnlhafhzlm9pks561rr73rqp-dosbox-0.74-3