LineageOS : upgrade nightly to unofficial I have a lineageos 14.1 nightly signed (downloaded from the official website) installed on my phone. I built a 14.1 from the sources following the official wiki (tagged unofficial build). Currently I have this message saying to wipe the /data :


  Can't install this package on top of incompatible data. Please try
  another package or run a factory reset


I don't understand why I should wipe my data, I thought that it was only when changing to a different ROM.

I want to know if there is a way to flash an unofficial without losing my data or why is that needed.
I found out that the release key is different, so a simple key migration solve it. The steps are explained on the Wiki.