Current Firefox versions have a cache inside omni.ja
itself. If you remove the file jsloader/resource/gre/modules/AddonUpdateChecker.jsm
from omni.ja
then Firefox should start looking at your modified modules/AddonUpdateChecker.jsm
instead. Additionally, you want to specify -purgecaches
command line flag instead of hunting down startup caches.
Side-note: it is generally helpful to set extensions.logging.enabled
to true
when debugging extension installation issues, this will print lots of additional information to Error Console. Of course, I don't know whether this additional information will be sufficient in your particular case.