Previously we could not override the input packages to docker at all as that had been shadowed due to the usage of inherit in all-package.nix. We are now mixing the "variable" variables for the build and the dependency declarations for the package and using callPackage as if each of the docker packages would be separate files that we evaluate. This now enables overriding e.g. iptables for a single verison of docker which previously was not feasible without importing the default.nix again (and passing different arguments). > pkgs.docker.override { iptables = pkgs.iptables-nftables-compat; }