these 2 derivations will be built:
  /nix/store/a2wx74kkpx7gsy2xb2wc7a6bkl9znmf6-freebuff-0.2.26.drv
  /nix/store/7gfp122k3hhgd0ka5krnqwvvjcbqrakm-check-freebuff.drv