unpacking 'https://github.com/NixOS/nixpkgs/archive/c043004d1c6985732bcc1cbc5a9c9aecbbb4e0f0.tar.gz' into the Git cache...
this derivation will be built:
  /nix/store/8cvdgvpsb559p147dry3rasqxwsnrlkl-bcachefs-module-6.18.49-3-lts.drv
these 2 paths will be fetched (227.90 MiB download, 615.43 MiB unpacked):
  /nix/store/s40h0m3746r0l287laa9sxa9345bkykf-linux-6.18.49
  /nix/store/8gsy6nldplfw12ylblabahhay8bv8xfx-linux-6.18.49-dev
copying path '/nix/store/s40h0m3746r0l287laa9sxa9345bkykf-linux-6.18.49' from 'https://cache.nixos.org'...
copying path '/nix/store/8gsy6nldplfw12ylblabahhay8bv8xfx-linux-6.18.49-dev' from 'https://cache.nixos.org'...
warning: download buffer is full; consider increasing the 'download-buffer-size' setting
building '/nix/store/8cvdgvpsb559p147dry3rasqxwsnrlkl-bcachefs-module-6.18.49-3-lts.drv'...