Could not reproduce with webcontent so far. Happens very often when debugging xpcshell or using the Browser Toolbox.
Spawned from Bug 1544820
- open Firefox
- open and close DevTools (that's just to load toolbox.js which we will use to repro the issue)
- open Browser Toolbox
- in Browser Toolbox, open Debugger, open
- set a breakpoint in the Toolbox constructor
- back to Firefox
- open DevTools (should break in the browser toolbox)
- back to the Browser Toolbox
- try to hover "ChromeUtils" on L34
This leads to a blank debugger for me. Copy pasting additional info I posted in the other bug:
I get the following exception :
console.error: (new TypeError("item is undefined", "resource://devtools/client/shared/components/reps/reps.js", 1497))
It seems to happen when hovering some variables in the debugger source editor. The stack is (removed everything not-devtools related):
It seems we are trying to render an object inspector without roots?