See https://github.com/browserpass/browserpass-native/issues/31 Additionally browserpass was removed from systemPackages, because it doesn't need to be installed, browsers will get the path to the binary from the native messaging host JSON.
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at http://nixos.org/nixos and in the manual in doc/manual.