@dmitri-shubin:

I used the following configuration string 'extensions=(libtbricks_storage.so=

{entry=tb_wt_backend_init,config=12345678"}

)'
It works ok on 2.3.1, but on 2.3.2 (develop) I got error:

[1410862592:372886][2174:e0b80df5ff7f0000], connection: key verbose contains a separator character (.): Invalid argument

But looks like the problem is that shared library name (libtbricks_storage.so), not 'verbose' key contains dot.

(gdb) bt
#0 __config_merge_scan (session=0x7ffff48e7000, key=0x7ffff4900000 "extensions", value=0x7ffff4913000 "(libtbricks_storage.so=

{entry=tb_wt_backend_init,config=140737295909344})", cp=0x7fffffffc308)
at /tb/builds/thd/sbn/2.6/src/thirdparty/wiredtiger/2.3.2/src/src/config/config_collapse.c:158
WT-1 0x00007ffff5f08620 in __config_merge_scan (session=0x7ffff48e7000, key=0x0,
value=0x7ffff488b0d8 "extensions=(libtbricks_storage.so={entry=tb_wt_backend_init,config=140737295909344}

),create,log=(enabled),cache_size=67108864,checkpoint=(wait=30)", cp=0x7fffffffc308)
at /tb/builds/thd/sbn/2.6/src/thirdparty/wiredtiger/2.3.2/src/src/config/config_collapse.c:184
WT-2 0x00007ffff5f080cb in __wt_config_merge (session=0x7ffff48e7000, cfg=0x7fffffffc3a8, config_ret=0x7ffff48e5300) at /tb/builds/thd/sbn/2.6/src/thirdparty/wiredtiger/2.3.2/src/src/config/config_collapse.c:364
WT-3 0x00007ffff5f0a7dc in wiredtiger_open (home=0x7ffff48dead8 "storage-cursor-perf", event_handler=0x0,
config=0x7ffff488b0d8 "extensions=(libtbricks_storage.so=

{entry=tb_wt_backend_init,config=140737295909344}

),create,log=(enabled),cache_size=67108864,checkpoint=(wait=30)", wt_connp=0x7fffffffc828)
at /tb/builds/thd/sbn/2.6/src/thirdparty/wiredtiger/2.3.2/src/src/conn/conn_api.c:1411