these 4 derivations will be built:
  /nix/store/yas3f04a164dflfzkz167qplrv70m7is-source.drv
  /nix/store/kimkhd6h9czyvs16z5w2i8jkzhqxmy92-mercat-0.3.4-zig-deps.drv
  /nix/store/imz71mdigdp2l4hiav2i6yzx1k2ysj92-mercat-0.3.4.drv
  /nix/store/5y49f5h8b3236123pafhb463qkv60bkk-check-mercat.drv