Chromebug For Firebug
Using the operating system command line, add the command line parameter 'chromebug'. For example to run Chromebug for firefox on windows:
This causes firefox to load chromebug as a XUL application, then Chromebug starts Firefox. For other operating systems, adjust the executable name; for other XUL applications use the appropriate starter application.
Open Firebug on your test page
Ok, you can do that
Click Inspect in Chromebug
Just like Firebug, for XUL. Slower and sometimes you have to coax it along
Select your target UI element
Here I am trying to figure out why the source line on Style is wrong, so I pick the style
Study the HTML for the panel
Here I can see that the object is in class "cssSelector", very often a good clue for the code in Firebug.
Searching for "cssSelector" shows css.js has the domplate that created the panel. There we see the the sourcelink is rule.sourcelink, so we look for that in the source
Then we are at the line we want: