these 2 derivations will be built:
  /nix/store/zychy3mw2b60rjb6f1h3wpg6avwj14kc-flake-inputs.drv
  /nix/store/fqqbkc1hj1lrqc4zy8s3lhwbxmcd8bhk-check-flake-inputs.drv