==21784== 8 bytes in 1 blocks are definitely lost in loss record 1 of 611
==21784==    at 0x4C2FD5F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==21784==    by 0x4E5B328: bson_realloc (bson-memory.c:150)
==21784==    by 0x4E5D2EF: bson_string_append (bson-string.c:156)
==21784==    by 0x4E5D6BE: bson_string_append_printf (bson-string.c:269)
==21784==    by 0x49060D: mongoc_collection_keys_to_index_string (mongoc-collection.c:990)
==21784==    by 0x490DE4: mongoc_collection_create_index_with_opts (mongoc-collection.c:1180)
==21784==    by 0x435BFD: test_index_w_write_concern (test-mongoc-collection.c:1740)
==21784==    by 0x479FF6: TestSuite_AddHelper (TestSuite.c:333)
==21784==    by 0x47A653: TestSuite_RunTest (TestSuite.c:602)
==21784==    by 0x47B0DF: TestSuite_RunNamed (TestSuite.c:911)
==21784==    by 0x47B21F: TestSuite_Run (TestSuite.c:947)
==21784==    by 0x415A53: main (test-libmongoc.c:1844)
==21784== 
==21784== 128 bytes in 1 blocks are definitely lost in loss record 555 of 611
==21784==    at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==21784==    by 0x4E5B263: bson_malloc (bson-memory.c:68)
==21784==    by 0x4E48626: _bson_impl_inline_grow (bson.c:118)
==21784==    by 0x4E487D9: _bson_grow (bson.c:206)
==21784==    by 0x4E48EFD: _bson_append_bson_begin (bson.c:452)
==21784==    by 0x4E4932F: bson_append_array_begin (bson.c:586)
==21784==    by 0x490EA9: mongoc_collection_create_index_with_opts (mongoc-collection.c:1198)
==21784==    by 0x435BFD: test_index_w_write_concern (test-mongoc-collection.c:1740)
==21784==    by 0x479FF6: TestSuite_AddHelper (TestSuite.c:333)
==21784==    by 0x47A653: TestSuite_RunTest (TestSuite.c:602)
==21784==    by 0x47B0DF: TestSuite_RunNamed (TestSuite.c:911)
==21784==    by 0x47B21F: TestSuite_Run (TestSuite.c:947)
==21784==