Perl6 JVM builds OK fails to run

[Simon Proctor]

Built the JVM Perl6 using rakudobrew and the 2017.02 branch. It builds OK
but gives :

java.nio.file.NoSuchFileException: blib/Perl6/BOOTSTRAP.jar
  in  (gen/jvm/ModuleLoader.nqp:88)
(And a bunch more stack trace)

Any idea how I can fix it?

Simon