Is there any objection to require Java 9 or 10 for *building* (not
necessarily running) Apache SIS? The project would continue to target
Java 8 at runtime for now, since SIS is not yet modularized. More
specifically, we would use the "javac -release" option, new in Java 9,
for targeting the older release.
The reason is that starting with Java 9, the programmatic use (from Java
code) of tools like javadoc is much easier. I also hope that a long
standing bug cause javadoc generation to fail on master will be fixed by
upgrading those tools.
The modularization of Apache SIS is a separated topic (not part of the
request in this email).