Looking Glass

This is the tool used to debug your GNOME shell extensions and gavascript code. To open Looking Glass, press Alt+F2, type in ‘lg’ and hit ‘Enter’. The Looking Glass window will open up.

Looking Glass is divided into tabs: Evaluator, Windows, Memory and Extensions. The Evaluator window is where you can type in random gavascript code. You can also use the picker at the left corner of Looking Glass, which you can use to select various elements of the GNOME shell and find out the element's name. The Windows tab shows which windows are active, while the Extensions tab shows the various extensions running on your system, along with any errors. If any extension runs into some error, the error will be displayed here.