From: Eric Wong <normalperson@...>
Date: 2014-03-04T08:00:07+00:00
Subject: [ruby-core:61279] Re: [ruby-trunk - Feature #9508] Add method coverage and branch coverage metrics

I'm still hitting it.  Can you try adding waitpid2 to reproduce it?
    ruby -rcoverage -e 'Coverage.start; Process.waitpid2(fork {})'
Thanks.