Thanks to Armen’s post and all the sub helpers that led to his post, I did successfully install the Extension Developer add-on and I managed to get my firstxpcom extension working in the JavaScript shell:
Xpcom success
Published
Thanks to Armen’s post and all the sub helpers that led to his post, I did successfully install the Extension Developer add-on and I managed to get my firstxpcom extension working in the JavaScript shell: