You can now open the browser debugger from the commandline (now also for mochitests!)

Gijs Kruitbosch gijskruitbosch at
Fri Oct 25 09:55:02 UTC 2013

Recently landed on m-c (should work on today's upcoming nightly): a 
--jsdebugger commandline flag! So opening firefox with --jsdebugger will 
immediately open the Browser Debugger.

What's more, a few minutes ago support landed on m-c for using this flag 
with mochitest-(plain|browser|chrome) for the same.

That means you can now do something like:

./mach mochitest-browser 
browser/base/content/test/general/browser_overflowScroll.js --jsdebugger

and it'll start the browser, open the debugger, and wait with running 
the test(s) until you hit the button on the mochitest UI (e.g. after 
you've set breakpoints etc.)

This should ease tracking down the cause of intermittent failures in 
these tests. Happy debugging!

~ Gijs

PS: details in if 
you're interested

More information about the firefox-dev mailing list