This is weird. After a week of usage, today, I see two extra extensions installed in my Nightly browser (custom built). The extensions are:
ADB Helper and
Valence. I did not install these and I don't remember giving any permission of that kind. These extensions seems to be featured/sponsored by Mozilla and somehow they have found a way to leak them into my browser.
So, I guess we have missed some code in addons manager, which still talks to Mozilla.
I think platform specific details are largely irrelevant here, but anyway:
OS: Mac OS 10.13.3 High Sierra
Commit:
https://github.com/MoonchildProductions ... 994d84c963 (latest master)
Below is my .mozconfig.
Found an old article about the exact same issue:
http://techdows.com/2015/08/shocking-fi ... d-ons.html