FULL PRODUCT VERSION :
Picked up _JAVA_OPTIONS: -Dawt.useSystemAAFontSettings=lcd
openjdk version "1.8.0_144"
OpenJDK Runtime Environment (IcedTea 3.5.1) (Slackware)
OpenJDK 64-Bit Server VM (build 25.144-b01, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Slackware64-current with multilib from AlienBB

A DESCRIPTION OF THE PROBLEM :
Problem is simple. When i try build OpenJFX with OpenJDK i got error:
A problem occurred evaluating root project 'rt-8u162-b00'.
> Unable to determine the version of Java in JDK_HOME at /usr/lib64/java

This error appears because of build.gradle script. This script try determinate Java version from second line:
java version "1.7.0_45"
Java(TM) SE Runtime Environment (build 1.7.0_45-b18)
Java HotSpot(TM) 64-Bit Server VM (build 24.45-b08, mixed mode)

But in OpenJDK "java -version" didn't look like these.


REPRODUCIBILITY :
This bug can be reproduced always.