Posted 3 months ago. Visible to the public.

How to get a backtrace if rspec (or any other ruby process) hangs with no output

If rspec hangs with no output and you dont get a backtrace neither with --backtrace nor by just killing it with crtl-c,
you can put the following in your spec/spec_helper.rb:

puts "rspec 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 the process with kill -USR1 <the pid> and you get the backtrace.


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Owner of this card:

Martin Schaflitzl
Last edit:
3 months ago
by Martin Schaflitzl
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Posted by Martin Schaflitzl to makandra dev
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