I want to inspect Firefox search bar popup window with Inspector by using Ctrl+Alt+Shift+I keys. But looks like impossible due to focus lost event. Is there some other method?
The focus issue has an official workaround:
It's hard to debug popups, because the browser hides them as soon as you click outside them. There is a way to disable this behavior. Click the toolbox menu and select Disable popup auto-hide.
Also note that:
This change is not persistent across browser restarts. When you close the browser toolbox, the setting will be cleared.