Add config for auto-package-update with cli output wrapper function

.emacs.d/init.el

@@ -315,6 +315,14 @@
   (add-hook 'yaml-mode-hook
             #'(lambda () (setq-local show-trailing-whitespace t))))
 
+(use-package auto-package-update :ensure t
+  :commands auto-package-update-cli
+  :config
+  ;; wrap apu-now to print to stdout for batch calling
+  (defun auto-package-update-cli ()
+    (cl-letf (((symbol-function 'apu--write-results-buffer) 'princ))
+      (auto-package-update-now))))
+
 ;;;; external packages (required)
 (use-package delight :ensure :demand)