Error in src/fiber.cr:501: instantiating 'new()'

  @@root = new
           ^~~

in src/fiber.cr:106: undefined method 'address' for UInt64

    @name = "main #{LibC.pthread_self.address}"
                                      ^~~~~~~

Rerun with --error-trace to show a complete error trace.
make: *** [Makefile:117: .build/crystal] Error 1