The problem was the JAVA_HOME environment variable. Given

    $ cat nbbuild/user.build.properties
    cluster.config=basic
    nbjdk.home=C:/b/j/Java/jdk1.7.0_60

It WORKS with JAVA_HOME set as

    $ echo $JAVA_HOME
    /b/j/Java/jdk1.7.0_60

If FAILS with

    $ echo $JAVA_HOME
    /b/j/Java/latest
    $ ls -l /b/j/Java/latest
    lrwxrwxrwx 1 err None 11 Feb  6 14:35 /b/j/Java/latest -> jdk1.8.0_31/

Does the problem has to do with ant, javac or NB? What's the meaning of setting nbjdk.home? (BTW, it failed around halfway through the build)

The issue is certainly nashorn library, some looking around I found the source for openjdk8-nashorn, and if the NB build was using the jkd8 nashorn, then I would expect the error. Why is it using nashorn from JAVA_HOME and not from main-silver/libs.nashorn during compilation? The one in main-silver seems to have some patches applied.

Here is the failure I was getting
 [nb-javac] C:\f\repos\main-silver\javascript2.editor\src\org\netbeans\modules\javascript2\editor\model\impl\PathNodeVisitor.java:84: error: constructor NodeVisitor in class NodeVisitor<T> cannot be applied to given types;
 [nb-javac] public class PathNodeVisitor extends NodeVisitor {
 [nb-javac]        ^
 [nb-javac]   required: LexicalContext
 [nb-javac]   found: no arguments
 [nb-javac]   reason: actual and formal argument lists differ in length
 [nb-javac]   where T is a type-variable:
 [nb-javac]     T extends LexicalContext declared in class NodeVisitor