[openhabian] Moving to OH3

I might have a (small?) blindspot, however the documentation says: Menu option 42 will do the upgrade..
Note that you have to be on the snapshot version of openhabian to get the correct option for that!

Not snapshot. On the master branch for the time being.
As told you the announcement.

Ups, wrong wording and yes I missed that announcement.
Retried from scratch using the changed openhab.config with clonebranch=openHAB3.
During install I got:

2020-11-25_14:01:02_UTC [openHABian] Updating myself from https://github.com/openhab/openhabian, openHAB3 branch... FAILED
2020-11-25_14:01:02_UTC [openHABian] The git repository on the public internet is not reachable.
2020-11-25_14:01:02_UTC [openHABian] We will continue trying to get your system installed, but this is not guaranteed to work.

Resulting in a stable openhabian version and a OH 2 installation, in other words something did not work (ATM?)!

[Edit:] Installing the openHAB3 version via the Option 42 failed as well

2020-11-25_15:17:24_CET [openHABian] Adding required keys to apt... OK
2020-11-25_15:17:26_CET [openHABian] Installing selected openHAB version...

…and no further output for 60 minutes.

Installing manually did work! It seems to me as if the install option of openhabian failed because the system was waiting for user input.

Set debugmode=maximumin /etc/openhabian.conf and try again.
You must not try clonebranch=openHAB3 though.

Thanks for this reply, however my setup is complete now using the manual install.
This time I did read your announcement and tried to give the requested feedback on the clonebranch=openHAB3 setting.
Looking onto htop while the system was hanging in the install showed a dpkg --status-fd 21 --configure --pending child-process (correct wording?) under the install process.