this derivation will be built:
  /nix/store/42b1qf4wz08iayljdij8r8ziswvdl47b-check-bernstein.drv
building '/nix/store/42b1qf4wz08iayljdij8r8ziswvdl47b-check-bernstein.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/42b1qf4wz08iayljdij8r8ziswvdl47b-check-bernstein.drv' on farm.numtide.com:50051
check-bernstein> bld4: building 42b1qf4wz08iayljdij8r8ziswvdl47b-check-bernstein.drv

upload niks3: ok