I tried to create the example.
If I follow the instructions I get these messages:
mkdir build && cd build
cmake -DWIFI_SSID="SOME_SSID" -DWIFI_PWD="SOME_PWD" ..
-- The C compiler identification is GNU 5.4.0
-- The CXX compiler identification is GNU 5.4.0
-- Found PythonInterp: /usr/bin/python (found version "2.7.15")
-- Arduino SDK version 1.0.5: /usr/share/arduino
-- Check for working C compiler: /usr/bin/avr-gcc
-- Check for working C compiler: /usr/bin/avr-gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/avr-g++
-- Check for working CXX compiler: /usr/bin/avr-g++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found Git: /usr/bin/git (found version "2.17.1")
-- CMAKE_BUILD_TYPE not given; setting to 'Debug'
-- Architectures included in amalgamation: freertosLWIP
-- The selected architecture is: freertosLWIP
-- Found Sphinx: /usr/bin/sphinx-build
-- Could NOT find LATEX (missing: LATEX_COMPILER)
-- Generating arduino_opcua
-- Generating featheresp32_WiFi for library WiFi
CMake Error at cmake/Platform/Arduino.cmake:896 (MESSAGE):
Value for .recipe.cpp.o.pattern not defined
Call Stack (most recent call first):
cmake/Platform/Arduino.cmake:1139 (get_recipe_flags)
cmake/Platform/Arduino.cmake:1227 (setup_arduino_library)
cmake/Platform/Arduino.cmake:538 (setup_arduino_libraries)
CMakeLists.txt:84 (generate_arduino_firmware)