title: What do these swift crashes mean?
body: <p>I have been trying to debug some issues in my app based on the logs that I see in Crashlytics. I am frequently coming across crashes with logs.  </p>
  
  <pre><code>libswiftCore.dylib -&gt; swift_unknownRetain_n + 44
  
  libswiftCore.dylib -&gt; swift_unknownRelease + 24
  </code></pre>
  
  <p>The exception thrown was  EXC_BAD_ACCESS KERN_INVALID_ADDRESS in both of these cases.</p>
  
  <p>I mostly see them when using blocks. I understand that these are segmentation faults, but shouldn't ARC handle the memory management gracefully to prevent these errors? Or am I missing some key point? </p>