title: How to debug Emacs lisp that makes Emacs crash/use 100% CPU?
body: <p>There's an external library I'm working with that frequently pegs my CPU. I'd like to help the author fix it (as I really like the library), but I don't know how to debug the crash properly.</p>
  
  <p>Any tips for debugging Emacs lisp? Bear in mind when it crashes Emacs doesn't work anymore and I have to kill it (so solutions within Emacs itself might not be helpful).</p>
  
  <p><strong>Edit</strong>: I should clarify that it is byte-compiled, and this issue doesn't always happen for others, so it may be specific to my architecture/init files. It is definitely related to this library though.</p>