I tried to give me a X-Mas present to ugrade from 2.5 to 3.0 according to the described 3 steps 
.
But the installer left me in the rain with 
:
The following packages have unmet dependencies:
openhab : Conflicts: openhab2 but 2.5.11-1 is to be installed
Breaks: openhab2 (< 3.0.0~) but 2.5.11-1 is to be installed
openhab-addons : Conflicts: openhab2 but 2.5.11-1 is to be installed
Breaks: openhab2 (< 3.0.0~) but 2.5.11-1 is to be installed
E: Unable to correct problems, you have held broken packages.
FAILED
FAILED (install openHAB)
Is this a known issue?
UPDATE1:
It seems this is due to pending changes which were coming in for OH2.5. So I did a normal system upgrade which failed in the end with problems with netfilter/iptables persistent packages. I apt removed those two and reinstalled. Then the 2.5 upgrade went through. Then I kicked the 3.0 upgrade again via Installer. A dialog appeared that the upgrade was successful but after that it showed that there was an error during install and that I should retry. Checking the console shows:
2020-12-25_12:56:47_CET [openHABian] Deleting mapdb persistence files... OK
2020-12-25_12:56:47_CET [openHABian] Migrating Amanda config... OK
2020-12-25_12:56:47_CET [openHABian] Migrating Samba and mount units...
$ systemctl stop smbd nmbd
$ systemctl disable --now srv-openhab2-addons.mount srv-openhab2-conf.mount srv-openhab2-userdata.mount srv-openhab2-sys.mount
$ systemctl enable --now srv-openhab-addons.mount srv-openhab-conf.mount srv-openhab-userdata.mount srv-openhab-sys.mount
Failed to enable unit: Unit file srv-openhab\x2daddons.mount does not exist.
FAILED (reenable mount units)
2020-12-25_12:56:55_CET [openHABian] Checking for default openHABian username:password combination... FAILED
2020-12-25_12:56:57_CET [openHABian] We hope you got what you came for! See you again soon ;)
Googling for that error shows: [OH3] openhabian-config path error in openHAB related (40) --> Upgrade to OH3 (42) · Issue #1272 · openhab/openhabian · GitHub
I applied the steps described there (Apply improvements/Samba) and that went through fine. Share is available.
When I try to make sure I have all the latest things now with update (02) it wants to downgrade java to 8 again and still fails to check the default username/password:
2020-12-25_13:12:39_CET [openHABian] Updating repositories and upgrading installed packages...
$ apt-get upgrade --yes
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:
rpi-eeprom-images triggerhappy
Use 'sudo apt autoremove' to remove them.
The following packages have been kept back:
libnode64 nodejs python-rpi.gpio
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
$ java_install_or_update Zulu8-32
$ java_zulu_update_available Zulu8-32
2020-12-25_13:12:44_CET [openHABian] Installing Java Zulu prerequisites (libc, libstdc++, zlib1g)... OK
CANCELED
$ java -version
openjdk version "11.0.9" 2020-10-20 LTS
OpenJDK Runtime Environment Zulu11.43+88-CA (build 11.0.9+11-LTS)
OpenJDK Client VM Zulu11.43+88-CA (build 11.0.9+11-LTS, mixed mode)
OK
2020-12-25_13:12:50_CET [openHABian] Checking for default openHABian username:password combination... FAILED
2020-12-25_13:12:52_CET [openHABian] We hope you got what you came for! See you again soon ;)
UPDATE2:
After a restart, MOTD shows still 2.5 and shows an error:
sed: can't read /var/lib/openhab2/etc/version.properties: No such file or directory
Updating the system still tries to install jdk8.
Invoking the UI shows the new style and my items and rules are still there - yay :D!
That nicely auto-generated startpage e.g. with a link to Grafana/Habpanel/Logviewer is gone (I guess by design) but invoking Grafana directy works still trying to find Habpanel and Logviewer though…
Tried /habpanel, but it simply shows
Connection lost! Trying to reconnect...
as it fails to load /app/widgets/clock/clock.widget.js with 404.
Tried :9001 for Logviewer but still seems to point to openhab2 log. Adapted /etc/systemd/system/frontail.service manually.
UPDATE3: seems related to 3.0 release · Issue #1308 · openhab/openhabian · GitHub - being on the wrong branch after the migration. Now switched to openHAB3 seems to fix some of the filesystem path related errors.