Run Ruby with warnings enabled. Without going crazy.

warning_filter.rb

require 'delegate'

module Support
  class WarningFilter < DelegateClass(IO)
    def write(line)
      super if line !~ /^\S+gems\/ruby\-\S+:\d+: warning:/
    end
  end
end

$stderr = Support::WarningFilter.new($stderr)

THANK YOU!