this derivation will be built:
  /nix/store/2ldg9xqzjn3bjai2j6p5i3a90rmrkmkh-check-showboat.drv
building '/nix/store/2ldg9xqzjn3bjai2j6p5i3a90rmrkmkh-check-showboat.drv'

upload niks3: ok