up to JDK 9 I didn't have problems upgrading, but since JDK 10 it always
wants to replace JDK 9, and I guess it will become worse with JDK 11 etc.
I've set "IgnorePkg = jdk9-openjdk jre9-openjdk jre9-openjdk-headless
openjdk9-doc openjdk9-src" in pacman.conf, so now I'm getting warnings
all the time, but I'm not sure what will happen with future updates.
As a Java developer, I need to be able to have multiple JDKs for