anchor.diff:  
     command = sub
       {
  +      package                 = default pkgs.postgresql package;
         blobs                   = optional bool;
         clean                   = optional bool;
         compress                = default 9 int;
  
positive.code:        else if isString v then "--${k}='${v}'"
         else "--${k}=${toString v}" ;
  
        # XXX: Use the latest pg_dump:
        pg_dump = pkgs.writeBashScript name ''
          ${optionalString (cfg.pgpass != null) "export PGPASSFILE='${cfg.pgpass}'"}
          exec ${cfg.package}/bin/pg_dump \
            ${concatMapAttrsSep " " mkArg args} \
            "$@"
        '';
  
negative.code: in {
    options.nixsap.apps.pgbackup = {
  
      user = mkOption {
        description = "User to run as";
        default = "pgbackup";
  