this derivation will be built:
  /nix/store/i588k0iq9nlskikq8q20izncnwlg9cwb-repo-sync.drv
building '/nix/store/i588k0iq9nlskikq8q20izncnwlg9cwb-repo-sync.drv' on 'grpc://[fddb:4344:343b:14b9:399:9324:19d9:3451]:50051?ca-cert=/run/nix-grpc-store/ca.crt&connect-timeout=5'
building '/nix/store/i588k0iq9nlskikq8q20izncnwlg9cwb-repo-sync.drv' on [fddb:4344:343b:14b9:399:9324:19d9:3451]:50051
repo-sync> stibnite: building i588k0iq9nlskikq8q20izncnwlg9cwb-repo-sync.drv
repo-sync> structuredAttrs is enabled

upload niks3: ok