As it turns out, Canonical decided to ship a new version of openjfx. (Incidentally, is there a place where one can see such version changes/decisions?)
The relevant information can be found in /var/log/apt/history.log
:
Start-Date: 2019-04-29 07:10:19
Commandline: apt upgrade
Requested-By: tannerli
Install: [snip]
Upgrade: [...]
openjfx:amd64 (8u161-b12-1ubuntu2, 11.0.2+1-1~18.04.2)
openjfx-source:amd64 (8u161-b12-1ubuntu2, 11.0.2+1-1~18.04.2)
libopenjfx-java:amd64 (8u161-b12-1ubuntu2, 11.0.2+1-1~18.04.2)
libopenjfx-jni:amd64 (8u161-b12-1ubuntu2, 11.0.2+1-1~18.04.2)
[...]
There's an open bug at LaunchPad and quite a few similar questions on various StackExchange sites concerning this, this one for example. None of those fit my specific needs. Seems there is no real solution to this day, only a
Workaround
Explictly downgrade all openjfx packages to the previous version:
$ sudo apt install openjfx=8u161-b12-1ubuntu2 libopenjfx-java=8u161-b12-1ubuntu2 libopenjfx-jni=8u161-b12-1ubuntu2 openjfx-source=8u161-b12-1ubuntu2
Hold back the affected packages, so that the next apt upgrade
won't break things again:
$ sudo apt-mark hold libopenjfx-java libopenjfx-jni openjfx openjfx-source
This will show up as info when you're upgrading next time:
$ sudo apt upgrade
[...]
The following packages have been kept back:
libopenjfx-java libopenjfx-jni openjfx openjfx-source
0 upgraded, 0 newly installed, 0 to remove and 4 not upgraded.