these 2 derivations will be built:
  /nix/store/5fndhb0mml7xm8pqpq3yrwfz761ibcff-flake-update.json.drv
  /nix/store/iqp7xlf05y3k4r0i5mw7wmlj1bak37lf-inputDerivation-flake-update.drv
building '/nix/store/5fndhb0mml7xm8pqpq3yrwfz761ibcff-flake-update.json.drv'...
building '/nix/store/iqp7xlf05y3k4r0i5mw7wmlj1bak37lf-inputDerivation-flake-update.drv'...