these 2 derivations will be built:
  /nix/store/v3gc4ry3f9yawwgcmv2y71jinkfmsw51-flake-fmt-1.0.0.drv
  /nix/store/465g7cg00j7dfxrnkhaysxvfz84x1vv7-merge-when-green-0.3.0.drv