unpacking 'https://github.com/NixOS/nixpkgs/archive/6774f7bc253789b113a4f39285dc0fa100abeacc.tar.gz' into the Git cache...
this derivation will be built:
  /nix/store/21gvbnm1xkgnfyc09gajb662yinjy7q6-bcachefs-module-7.0.0-34-generic.drv
building '/nix/store/21gvbnm1xkgnfyc09gajb662yinjy7q6-bcachefs-module-7.0.0-34-generic.drv'...