Test program:

#include <boost/thread/thread.hpp>
#include <mongo/client/dbclient.h>
#include <mongo/client/connpool.h>

using namespace mongo;

void thread_run() {
DBClientConnection conn;
std::string errmsg;
if ( ! conn.connect( "127.0.0.1:27017" , errmsg ) )

{ cout << "couldn't connect : " << errmsg << endl; }

}

int main() {
boost::thread myThread(&thread_run);
myThread.interrupt();
myThread.join();
return 0;
}

Fails with either:
Segmentation fault: 11
or:
libc++abi.dylib: pure virtual method called
Abort trap: 6