The problem may be that if the application is statically linked, the linker notices that there are no calls to `wiredtiger_config_parser_open` and omits it from the binary.  Then when the extension is loaded, the symbol is missing.

If that is what's going on, the cleanest solution is probably to include an entry in the extension API for all functions in the public API that an extension could conceivably call.  I don't want extensions to have to link against wiredtiger: that's a nightmare waiting to happen.