root@cuixiaoyuan-virtual-machine:/home/DJI/payload_SDK_V2.2.1-build.315/sample/platform/linux/manifold2/project/build# cmake ..
-- The C compiler identification is GNU 5.5.0
-- The CXX compiler identification is GNU 5.5.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- 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/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Error at CMakeLists.txt:56 (target_link_libraries):
Target "test_demo" of type EXECUTABLE may not be linked into another
target. One may link only to STATIC or SHARED libraries, or to executables
with the ENABLE_EXPORTS property set.