In gradle 4 the default location of classes when using has changed from: Java, `src/main/java` -> build/classes/main .. to .. Java, `src/main/java` -> build/classes/java/main
This breaks some parts of the FX build .. which eventually is going to need gradle 4.1 for JDK 10 and already does for some testing purposes so I am being bitten by this on an almost daily basis.
The fix and a few more details are in-line in the bug : https://bugs.openjdk.java.net/browse/JDK-8185358 -phil.
