I have a similar problem. I’ve installed my Chrome extension in FF nightly. The only modification I’ve made so far is to add the applications->gecko key to my manifest.json.
I’ve added console log statements in some of my content scripts, but I don’t see them appearing anywhere. Also in the debugger pane, I only see the sources of the page, I don’t see any of my content or background scripts.
I guess I’ll try stripping things out until it shows up?