Crashing Script Editor in Sierra 10.12.4 – sth for the Apple bug radar?

Not sure if others are seeing this, but here I can reproducibly crash Script Editor by clicking on the disclosure triangle next to an Automation object local variable in the Safari Debugger Scope Chain panel (local or global variables section.

If you are a user of Keyboard Maestro’s Execute JavaScript for Automation actions, running macOS Sierra 10.12.4, and are seeing this too, then probably worth alerting Apple.

Steps to reproduce:

  1. in Safari, under the (Develop menu item and the local machine name) enable the option:
    “Automatically show web inspector for JS Contexts”
    (as per
  2. Run this script, including a debugger; line, in Script Editor:
(() => {
    'use strict';

    var a = Application.currentApplication(),
	sa = (a.includeStandardAdditions = true, a);

  1. When the Safari Debugger window appears, click on the disclosure triangle for the sa or a variable in the scope chain (local variables) panel at right.
  2. BANG: here, at least, Script Editor immediately crashes.

Just to confirm it is a macOS Sierra issue, I was able to successfully run this using Safari 10.1 (11603. on macOS 10.11.6 without any issues:

'use strict';
(function run() {      // this will auto-run when script is executed

// Compatible with ES5
// Safari 10.1 (11603. on macOS 10.11.6

  var a = Application.currentApplication(),
  sa = (a.includeStandardAdditions = true, a);

}  // END of function run()

I was able to expand both the "a" and "sa" variables without any problems.

One more of many issues/reasons to NOT upgrade to macOS Sierra.
I see no compelling reason to do so.