Hi, I would highly recommend to build the jigsaw andjdk9 ea builds with '--with-version-patch=1'. This will result in a java.version of the form "9.0.0.1-..." and give people a chance to "really" test the new Java versioning scheme. Otherwise they will only detect potential problems with the first update version, which will be the first one to have a more complex version number.
Currently, the Java version is simply "9" which is the short hand form of "9.0.0.0" and people are only testing their old code with this simplified version number. But you don't see problems like for example "8149519: Investigate implementation of java.specification.version" [1] as long as we only use the simplified version scheme. Regards, Volker [1] https://bugs.openjdk.java.net/browse/JDK-8149519
