Check for tool-bar-mode (fix 25.1 travis test)

core/core-ui.el

@@ -115,7 +115,8 @@ mode is detected.")
 
 (tooltip-mode -1) ; relegate tooltips to echo area only
 (menu-bar-mode -1)
-(tool-bar-mode -1)
+(when (fboundp 'tool-bar-mode)
+  (tool-bar-mode -1))
 (when (display-graphic-p)
   (scroll-bar-mode -1)
   ;; buffer name  in frame title

test/init.test.el

@@ -1,7 +1,8 @@
 ;;; init.el
 
 (require 'core (concat user-emacs-directory "core/core"))
-(setq debug-on-error nil)
+
+(setq-default debug-on-error nil)
 
 (doom! :feature evil
        :private hlissner)