
First because IFD (import-from-derivation) is not allowed on hydra.nixos.org, and second because without https://github.com/NixOS/hydra/pull/825 hydra-eval-jobs crashes instead of skipping aggregated jobs which fail (here because they required an IFD).
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at https://nixos.org/nixos and in the manual in doc/manual.