You're reading the documentation for an older, but still supported version (1.33.4).
For information on the latest version, please have a look at 1.33.5.
For information on the latest version, please have a look at 1.33.5.
7.3 Build Error: Poco Not Found
A. Error Case
During build, the link step fails with undefined references to Poco:: symbols.
B. Root Cause Analysis
The Poco C++ Libraries are missing from your system, or -lPocoNet -lPocoFoundation is missing from the link line.
C. Solution
Install the dependency manually:
sudo apt install libpoco-dev
Then re-run CMake:
cd build && cmake .. && make
If Poco is installed, add -lPocoNet -lPocoFoundation after libDRFL.a on the link line (see Linking Library).