Ruby Beta - Error while running github search example

I have CB Server 7.0 on my machine and I tried to execute examples both from docs and from examples from search with beer-sample installed. I get the following error and its consistent

ruby search.rb

libc++abi.dylib: terminating with uncaught exception of type std::1::future_error: The state of the promise has already been set.

zsh: abort      _      _ruby search.rb