 (defvar edebug-new-definition-function)
 
 (defvar warning-fill-column)  ; only in Emacs 27 and later
+
+;; ERT resource variables only appeared in Emacs 28.
+(defvar ert-resource-directory-trim-left-regexp)
+(defvar ert-resource-directory-format)
 
 (defun elisp/ert/run-batch-and-exit ()
   "Run ERT tests in batch mode.

         (source-dir (getenv "TEST_SRCDIR"))
         (temp-dir (getenv "TEST_TMPDIR"))
         (temporary-file-directory (concat "/:" temp-dir))
         (report-file (getenv "XML_OUTPUT_FILE"))
         (random-seed (or (getenv "TEST_RANDOM_SEED") ""))
         (shard-count (string-to-number (or (getenv "TEST_TOTAL_SHARDS") "1")))

(require 'debug)
(require 'edebug)
(require 'ert)
(require 'ert-x)
(require 'format)
(require 'nadvice)
(require 'pp)
