I don't know if it really is a bug in Ruby, but I was using gulp-node-sass (which in turn uses the sass gem), and it yelled at me this:
Updated by JoelSanchez (Joel Sánchez López) over 3 years ago
What do you mean? All I have is that dump, and information about my system and what I was doing just before that happened.
I was compiling Sass files, and I have not been able to reproduce the issue again.
This is Arch Linux, the kernel is "x86_64 Linux 4.6.4-1-ARCH".