this derivation will be built:
  /nix/store/wj7qw7vin0fjxnggi27q3ydffkh25z2h-check-showboat.drv
building '/nix/store/wj7qw7vin0fjxnggi27q3ydffkh25z2h-check-showboat.drv' on 'grpc://farm.numtide.com:50051?client-cert=/run/secrets/vars/per-machine/bld1/nix-farm-ci/crt&client-key=/run/secrets/vars/per-machine/bld1/nix-farm-ci/key&connect-timeout=20&system=aarch64-linux'
building '/nix/store/wj7qw7vin0fjxnggi27q3ydffkh25z2h-check-showboat.drv' on farm.numtide.com:50051
check-showboat> bld3: building wj7qw7vin0fjxnggi27q3ydffkh25z2h-check-showboat.drv

upload niks3: ok