见 Creating OPC UA Clients with security support for detailed instructions for setting up the Unified Automation SDK including security extensions.
When building at the top level, you have to specify the path to the UACPP SDK:
configure UACPP_PREFIX=/path/to/sdk
If you are not building at the top level, this setting has to be given to qmake:
qmake </path/to/qtopcua> -- UACPP_PREFIX=/path/to/sdk
The output of the configuration step indicates whether the detection was successful:
Unified Automation C++ SDK ............. yes
