this derivation will be built:
  /nix/store/4q6h18ca8lfqd7zigrsahd097raj64kh-inputDerivation-effect-update-packages.drv
these 2 paths will be fetched (83.2 KiB download, 298.4 KiB unpacked):
  /nix/store/nrhw8ay4r9vyb0b6sj7rz91wmhx9aa15-nix-2.34.8-dev
  /nix/store/2crkfkrfs2swaibqn5m20b8blahb5n23-nix-perl-2.34.8
copying path '/nix/store/2crkfkrfs2swaibqn5m20b8blahb5n23-nix-perl-2.34.8' from 'https://cache.nixos.org'...
copying path '/nix/store/nrhw8ay4r9vyb0b6sj7rz91wmhx9aa15-nix-2.34.8-dev' from 'https://cache.nixos.org'...
building '/nix/store/4q6h18ca8lfqd7zigrsahd097raj64kh-inputDerivation-effect-update-packages.drv'...