these 2 derivations will be built:
  /nix/store/cdixxd1fvdk37lgb4g52sapb17xpr1kc-formatter.drv
  /nix/store/6afjq7x16i2pi2sb2krc1ysf4w61daj7-check-formatting.drv
this path will be fetched (1.2 MiB download, 3.4 MiB unpacked):
  /nix/store/58wahpfp88r4girryh9b45m22l51lb0k-nixpkgs-fmt-1.3.0