To all ubuntu Maven users. Do NOT install maven using sudo apt install maven
Install by direct download only from https://maven.apache.org/download.cgi BECAUSE: "I seem to remember they [ubuntu] have their own build of Maven which differs from the Apache source. ( https://bugs.launchpad.net/ubuntu/+source/maven/+bug/1754602 suggests it's a known bug in their packaging/build? ) If you download Maven from http://maven.apache.org/download.cgi and follow the instructions in http://maven.apache.org/install.html then you shouldn't see those warnings. " ‐------------------- The Java 11 warning mentions that "/usr/share/maven/lib/guice.jar" has a class named "com.google.inject.internal.cglib.core.$ReflectUtils$1" This looks suspect because the official Maven distribution uses the "no-AOP" version of Guice which doesn't contain any CGLIB classes. It suggests that whoever provided that copy of Maven has replaced the "no-AOP" version with the "AOP" version, and this will cause warnings on Java 11. (The "AOP" version uses CGLIB which currently relies on certain reflective access that Java 11 warns about - whereas the "no-AOP" version doesn't.)