unpacking 'https://github.com/NixOS/nixpkgs/archive/a1bab9e494f5f4939442a57a58d0449a109593fe.tar.gz' into the Git cache...
this derivation will be built:
  /nix/store/fw87fywj3fcysg0cw8xvh0phwy1iv813-bcachefs-module-7.0.0-26-generic.drv
building '/nix/store/fw87fywj3fcysg0cw8xvh0phwy1iv813-bcachefs-module-7.0.0-26-generic.drv'...