Steps to reproduce:

$ gradle :graphcs:test
...
validating packages for modules/javafx.graphics/src/main/java
*** ERROR: File location <modules/javafx.graphics/src/main/java/javafx/scene/package-info.java> does not match package name <example>

FAILURE: Build failed with an exception.

* Where:
Build file 'build.gradle' line: 266

* What went wrong:
Execution failed for task ':graphics:validateSourceSets'.
> FAIL: Package validation failed

The converted package-info.java file has an example with "package example;", which is being picked up as the package for that file by the (too simplistic) parsing done by validateSourceSets in build.gradle.