rspec backtrace

Get backtrace if rspec hangs with not input

# Source: https://github.com/rspec/rspec-rails/issues/1353#issuecomment-93173691

# Add to spec/spec_helper.rb

puts "rspec pid: #{Process.pid}"

trap 'USR1' do
  threads = Thread.list

  puts
  puts "=" * 80
  puts "Received USR1 signal; printing all #{threads.count} thread backtraces."

  threads.each do |thr|
    description = thr == Thread.main ? "Main thread" : thr.inspect
    puts
    puts "#{description} backtrace: "
    puts thr.backtrace.join("\n")
  end

  puts "=" * 80
end

# Then $ kill -USR1 <the pid>