anchor.diff:      services.postgresql.authentication =
         ''
           # Generated file; do not edit!
  -        local all all              ident sameuser
  +        local all all              ident ${optionalString pre84 "sameuser"}
           host  all all 127.0.0.1/32 md5
           host  all all ::1/128      md5
         '';
  
positive.code:       ${cfg.extraConfig}
      '';
  
  in
  
  {
  
negative.code:   postgresqlAndPlugins = pg:
      if cfg.extraPlugins == [] then pg
      else pkgs.buildEnv {
        name = "postgresql-and-plugins-${(builtins.parseDrvName pg.name).version}";
        paths = [ pg ] ++ cfg.extraPlugins;
        postBuild =
          ''
  