title: Unable to Debug Multi-Threaded Application with gdb
body: <p>I am debugging a multi-threaded application with gdb, but when I start the program in gdb I get the warning:</p>
  
  <blockquote>
    <p>warning: Unable to find libthread_db matching inferior's thread library, thread debugging will not be available.</p>
  </blockquote>
  
  <p>I can still debug, but I can't debug anything other than the main thread. I have read forums that suggest installing the packages libthread-db1 and glibc-dbg, but this does not correct the problem for me.</p>
  
  <p>On my machine I have the 3 files <code>/lib/libthread_db.so.1</code>, <code>/lib/.debug/libthread_db-1.0.so</code>, and <code>/lib/libthread_db-1.0.so</code>.  I tried creating symbolic links in <code>/lib</code> with the name <code>libthread_db.so</code>, one time pointing at the <code>/lib/libthread_db.so.1</code> file, and another time pointing at the <code>/lib/libthread_db-1.0.so</code> file, and also I created the symbolic link <code>/lib/.debug/libthread_db.so</code> pointing to <code>/lib/.debug/libthread_db-1.0.so</code>, all with no luck.</p>
  
  <p>In gdb I have tried setting <code>libthread-db-search-path</code> to <code>/lib</code> (with the symlink once set to <code>libthread_db.so.1</code>, and once to <code>libthread_db-1.0.so</code>, and also set to <code>/lib/.debug</code>.</p>
  
  <p>Any suggestions? I am using Angstrom Linux v2.6.39 for the BeagleBoard-xm.</p>