After some more testing and frustration I've found that after updating JaCoCo to 0.8.2 the newest OpenJDK 11 build works, as does the OpenJDK 10 provided by Ubuntu.
The OpenJDK 8 version now provided by Ubuntu doesn't.
After some more testing and frustration I've found that after updating JaCoCo to 0.8.2 the newest OpenJDK 11 build works, as does the OpenJDK 10 provided by Ubuntu.
The OpenJDK 8 version now provided by Ubuntu doesn't.