* thread #1: tid = 2090207, 0x000000000040f047 mongo_c_test`mongoc_counter_clients_active_add(val=1) + 39 at mongoc-counters.defs:42, name = 'mongo_c_test', stop reason = signal SIGSEGV: invalid address (fault address: 0x7ffff8035920)
    frame #0: 0x000000000040f047 mongo_c_test`mongoc_counter_clients_active_add(val=1) + 39 at mongoc-counters.defs:42
   39   COUNTER(cursors_disposed,       "Cursors",      "Disposed",            "The number of disposed cursors.")
   40  
   41  
-> 42   COUNTER(clients_active,         "Clients",      "Active",              "The number of active clients.")
   43   COUNTER(clients_disposed,       "Clients",      "Disposed",            "The number of disposed clients.")
   44  
   45  
(lldb) bt
* thread #1: tid = 2090207, 0x000000000040f047 mongo_c_test`mongoc_counter_clients_active_add(val=1) + 39 at mongoc-counters.defs:42, name = 'mongo_c_test', stop reason = signal SIGSEGV: invalid address (fault address: 0x7ffff8035920)
  * frame #0: 0x000000000040f047 mongo_c_test`mongoc_counter_clients_active_add(val=1) + 39 at mongoc-counters.defs:42
    frame #1: 0x000000000040c250 mongo_c_test`mongoc_counter_clients_active_inc + 16 at mongoc-counters.defs:42
    frame #2: 0x000000000040c17b mongo_c_test`_mongoc_client_new_from_uri(uri=0x000000000068a2c0, topology=0x000000000068aa60) + 571 at mongoc-client.c:778
    frame #3: 0x000000000040bf05 mongo_c_test`mongoc_client_new(uri_string="mongodb://localhost:27017") + 101 at mongoc-client.c:636
    frame #4: 0x000000000040aaea mongo_c_test`main(argc=1, argv=0x00007fffffffe098) + 58 at main.c:32
    frame #5: 0x00007ffff7412b15 libc.so.6`__libc_start_main + 245
    frame #6: 0x000000000040a9e9 mongo_c_test`_start + 41
(lldb) f 0
frame #0: 0x000000000040f047 mongo_c_test`mongoc_counter_clients_active_add(val=1) + 39 at mongoc-counters.defs:42
   39   COUNTER(cursors_disposed,       "Cursors",      "Disposed",            "The number of disposed cursors.")
   40  
   41  
-> 42   COUNTER(clients_active,         "Clients",      "Active",              "The number of active clients.")
   43   COUNTER(clients_disposed,       "Clients",      "Disposed",            "The number of disposed clients.")
   44  
   45  
(lldb) f 1
frame #1: 0x000000000040c250 mongo_c_test`mongoc_counter_clients_active_inc + 16 at mongoc-counters.defs:42
   39   COUNTER(cursors_disposed,       "Cursors",      "Disposed",            "The number of disposed cursors.")
   40  
   41  
-> 42   COUNTER(clients_active,         "Clients",      "Active",              "The number of active clients.")
   43   COUNTER(clients_disposed,       "Clients",      "Disposed",            "The number of disposed clients.")
   44  
   45  
(lldb) f 2
frame #2: 0x000000000040c17b mongo_c_test`_mongoc_client_new_from_uri(uri=0x000000000068a2c0, topology=0x000000000068aa60) + 571 at mongoc-client.c:778
   775     }
   776  #endif
   777 
-> 778     mongoc_counter_clients_active_inc ();
   779 
   780     return client;
   781  }
(lldb) f 3
frame #3: 0x000000000040bf05 mongo_c_test`mongoc_client_new(uri_string="mongodb://localhost:27017") + 101 at mongoc-client.c:636
   633 
   634     topology = mongoc_topology_new(uri, true);
   635 
-> 636     client = _mongoc_client_new_from_uri (uri, topology);
   637     if (!client) {
   638        mongoc_topology_destroy (topology);
   639     }
(lldb) f 4
frame #4: 0x000000000040aaea mongo_c_test`main(argc=1, argv=0x00007fffffffe098) + 58 at main.c:32
   29       /*
   30        * Create a new client instance
   31        */
-> 32       client = mongoc_client_new("mongodb://localhost:27017");
   33  
   34       /*
   35        * Get a handle on the database "db_name" and collection "coll_name"