When I compiled a module using the Zabbix v2.x headers it fails to work in Zabbix v3. Likewise, if I compile with v3 headers, it fails in Zabbix v2.x.

In both cases, a blank value is returned with no errors when queried via `zabbix_get` for any item in the compiled module.

Both modules are using the documented v1 module API which should work fine in either version.