This happened in a pathological case in Nixpkgs: the "grub" job is evaluated for i686-linux and x86_64-linux, but in the latter case it returns the same derivation as in the former case. So only one build should be added.
This happened in a pathological case in Nixpkgs: the "grub" job is evaluated for i686-linux and x86_64-linux, but in the latter case it returns the same derivation as in the former case. So only one build should be added.