title: What's the meaning of the EXC_BREAKPOINT code and subcode?
body: <p>Usually when I set lldb watchpoints, when they're hit, lldb says watchpoint hit old value: new value.  However, I set a watchpoint on an address that seems to be getting written to inside a 3rd party library (libjpeg-turbo) and instead of the usual watchpoint hit, I'm seeing EXC_BREAKPOINT code=258, subcode=0xADDRESS.</p>
  
  <p>In all cases, I can see that the subcode must be the address, as it's always equal to the address or close to the one I set the watchpoint to.  Can anyone confirm this?</p>
  
  <p>If I delete the watchpoint and keep going, lldb won't pause with EXC_BREAKPOINT.  But what does the code mean and where can I find some offical documentation on this?</p>
  
  <p>The exc_types.h doesn't give any detailed information on it.</p>