title: GDB Windows ?? in Backtraces
body: <p>Using MinGW GDB version 7.6, get a lot of backtraces like this:</p>
  
  <pre><code>(gdb) bt
  #0  0x000000007703d256 in ntdll!RtlEnterCriticalSection ()
     from C:\Windows\SYSTEM32\ntdll.dll
  #1  0x0000000000000000 in ?? ()
  </code></pre>
  
  <p>Which isn't exactly useful.</p>
  
  <p>Why is this?  Is there anyway to get anything more useful?  It's absolutely painful to try and figure out what a complicated, multi-threaded program was doing when an error happened when <strong>this</strong> is the backtrace that I get.</p>