anchor.diff:        exec ${askPassword} "$@"
       '';
   
  -  knownHosts = map (h: getAttr h cfg.knownHosts) (attrNames cfg.knownHosts);
  +  knownHosts = attrValues cfg.knownHosts;
   
     knownHostsText = (flip (concatMapStringsSep "\n") knownHosts
       (h: assert h.hostNames != [];
  
positive.code:                     (data.publicKey != null && data.publicKeyFile == null);
          message = "knownHost ${name} must contain either a publicKey or publicKeyFile";
        });
  
      # SSH configuration. Slight duplication of the sshd_config
      # generation in the sshd service.
  
negative.code:             };
              hostNames = mkOption {
                type = types.listOf types.str;
                default = [ name ] ++ config.extraHostNames;
                description = ''
                  DEPRECATED, please use <literal>extraHostNames</literal>.
                  A list of host names and/or IP numbers used for accessing
                  the host's ssh service.
                '';
              };
              extraHostNames = mkOption {
                type = types.listOf types.str;
                default = [];
                description = ''
                  A list of additional host names and/or IP numbers used for
                  accessing the host's ssh service.
                '';
              };
              publicKey = mkOption {
  