class Spec::Runner::QuietBacktraceTweaker

def tweak_backtrace(error)
  return if error.backtrace.nil?
  tweaked = error.backtrace.collect do |message|
    clean_up_double_slashes(message)
    kept_lines = message.split("\n").select do |line|
      IGNORE_PATTERNS.each do |ignore|
        break if line =~ ignore
      end
    end
    kept_lines.empty?? nil : kept_lines.join("\n")
  end
  error.set_backtrace(tweaked.select {|line| line})
end