-- The C compiler identification is GNU 9.4.0
-- The CXX compiler identification is GNU 9.4.0
-- 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
-- Found ament_cmake: 0.9.12 (/opt/ros/foxy/share/ament_cmake/cmake)
-- Found PythonInterp: /usr/bin/python3 (found suitable version "3.8.10", minimum required is "3") 
-- Using PYTHON_EXECUTABLE: /usr/bin/python3
-- Found rclcpp: 2.4.3 (/opt/ros/foxy/share/rclcpp/cmake)
-- Using all available rosidl_typesupport_c: rosidl_typesupport_fastrtps_c;rosidl_typesupport_introspection_c
-- Found rosidl_adapter: 1.3.1 (/opt/ros/foxy/share/rosidl_adapter/cmake)
-- Found OpenSSL: /usr/lib/x86_64-linux-gnu/libcrypto.so (found version "1.1.1f")  
-- Found FastRTPS: /opt/ros/foxy/include  
-- Using all available rosidl_typesupport_cpp: rosidl_typesupport_fastrtps_cpp;rosidl_typesupport_introspection_cpp
-- Found rmw_implementation_cmake: 1.0.4 (/opt/ros/foxy/share/rmw_implementation_cmake/cmake)
-- Using RMW implementation 'rmw_fastrtps_cpp' as default
-- Looking for pthread.h
-- Looking for pthread.h - found
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Failed
-- Looking for pthread_create in pthreads
-- Looking for pthread_create in pthreads - not found
-- Looking for pthread_create in pthread
-- Looking for pthread_create in pthread - found
-- Found Threads: TRUE  
-- Configuring done
-- Generating done
-- Build files have been written to: /home/sxj/ros2_ws/build/example_topic
Scanning dependencies of target sub_node
Scanning dependencies of target pub_node
[ 50%] Building CXX object CMakeFiles/pub_node.dir/src/pub_node.cpp.o
[ 50%] Building CXX object CMakeFiles/sub_node.dir/src/sub_node.cpp.o
[ 75%] Linking CXX executable pub_node
[ 75%] Built target pub_node
[100%] Linking CXX executable sub_node
[100%] Built target sub_node
-- Install configuration: ""
-- Installing: /home/sxj/ros2_ws/install/example_topic/lib/example_topic/pub_node
-- Set runtime path of "/home/sxj/ros2_ws/install/example_topic/lib/example_topic/pub_node" to ""
-- Installing: /home/sxj/ros2_ws/install/example_topic/lib/example_topic/sub_node
-- Set runtime path of "/home/sxj/ros2_ws/install/example_topic/lib/example_topic/sub_node" to ""
-- Installing: /home/sxj/ros2_ws/install/example_topic/include/example_topic/
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic//launch
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic//launch/talker_listener_launch.py
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic//config
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/ament_index/resource_index/package_run_dependencies/example_topic
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/ament_index/resource_index/parent_prefix_path/example_topic
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic/environment/ament_prefix_path.sh
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic/environment/ament_prefix_path.dsv
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic/environment/path.sh
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic/environment/path.dsv
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic/local_setup.bash
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic/local_setup.sh
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic/local_setup.zsh
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic/local_setup.dsv
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic/package.dsv
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/ament_index/resource_index/packages/example_topic
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic/cmake/example_topicConfig.cmake
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic/cmake/example_topicConfig-version.cmake
-- Installing: /home/sxj/ros2_ws/install/example_topic/share/example_topic/package.xml