nix-repl> :l <nixpkgs>
Added 11389 variables.

nix-repl> builtins.concatMap (drv: if drv.meta.isGutenprint then [drv] else []) (builtins.attrValues 
error: Please be informed that this pseudo-package is not the only part of
Nixpkgs that fails to evaluate. You should not evaluate entire Nixpkgs
without some special measures to handle failing packages, like those taken
by Hydra.


how do I evaluate this properly?