Major Description
The problem is that we have a fragment for the logger which needs to be loaded in the startup phase. We compile the bundles with Java 11 which results in a
Require-Capability: osgi.ee;filter:="(&(osgi.ee=JavaSE)(version=11))"
manifest entry. We during build we get an error that a bundle requirement is not met.
We then discovered that the karaf-maven-plugin uses "1.8" as default value for the javase option. Changing that to "11" results in a compile error because this version is not supported.
Therefore I suggest to add Java 10 and Java 11 to enum org.apache.karaf.profile.assembly.Builder.JavaVersion. That enables support for this Java version also.
In my local tests this solved the compile issue when setting the javase option to 11.