title: Emacs debug-on-error not triggering for longlines-mode error
body: <p>I'm running into a repeated error where switching to certain files results in seeing the following error 50% of the time.[0]</p>
  
  <pre><code>Symbol's function definition is void: longlines-mode
  </code></pre>
  
  <p>The file switch fails when I see this error. </p>
  
  <p>In the <code>*Messages*</code> buffer, I see:</p>
  
  <pre><code>run-hooks: Symbol's function definition is void: longlines-mode
  </code></pre>
  
  <p>As far as I can tell, nothing in my <code>init.el</code> or referenced files uses <code>longlines-mode</code>. </p>
  
  <p>After running <code>(setq debug-on-error t)</code>, I continue to see the message, but do not get dropped into a backtrace.</p>
  
  <p>Running <code>GNU Emacs 24.4.1 (x86_64-apple-darwin13.4.0, NS apple-appkit-1265.21) of 2014-10-20 on builder10-9.porkrind.org</code></p>
  
  <p>My questions are </p>
  
  <p>1) How do I track down this error? </p>
  
  <p>2) Why does <code>debug-on-error</code> not work? </p>
  
  <p>[0] When I say 50%, I literally mean 50%. If I repeatedly run <code>timeclock-visit-timelog</code> (just one file where it happens), I will get the error. The next run I won't. The run after I will...</p>
  
  <p>The behavior does not happen for all file types. <code>.java</code> files are not affected. <code>.org</code> files are. Opening IRC is. </p>