unpacking 'https://github.com/NixOS/nixpkgs/archive/a7868a727837f3c09cee2ce0ca671c76b1589fed.tar.gz' into the Git cache...
this derivation will be built:
  /nix/store/6z2f76mlpzp3c6pkzsb7bbw8y9nhhrkk-bcachefs-module-6.18.55-1-lts.drv
these 2 paths will be fetched (230.05 MiB download, 621.52 MiB unpacked):
  /nix/store/l55iycmwfsvc9nrb97z9f1cr3dykjqvx-linux-6.18.55
  /nix/store/ks0iyfj7hdc5ll5h0hwir4dga9282rqf-linux-6.18.55-dev
copying path '/nix/store/l55iycmwfsvc9nrb97z9f1cr3dykjqvx-linux-6.18.55' from 'https://cache.nixos.org'...
copying path '/nix/store/ks0iyfj7hdc5ll5h0hwir4dga9282rqf-linux-6.18.55-dev' from 'https://cache.nixos.org'...
warning: download buffer is full; consider increasing the 'download-buffer-size' setting
building '/nix/store/6z2f76mlpzp3c6pkzsb7bbw8y9nhhrkk-bcachefs-module-6.18.55-1-lts.drv'...