lazyparser
commented
6 years ago add_executable cannot create target "talker" because another target with the same name already exists.
表示重名了，是不是还有比的packages存在。
另外如果IDE不行的话，换一个呗。推荐 vim 或者 vscode + ROS 插件（也是柴老师推荐的）
后续问题可以去 https://q.droid.ac.cn 上问，人多一些
daniao2017
用那个推荐的编译器写基础教程时出现的问题！！！！！！！！！！ 就是那啥catkin_ws过不了 CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:154 (add_executable): add_executable cannot create target "talker" because another target with the same name already exists. The existing target is an executable created in source directory "/home/daniao/catkin_ws/src/beginner_tutorials". See documentation for policy CMP0002 for more details.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/opt/ros/kinetic/lib/libroscpp.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/usr/lib/x86_64-linux-gnu/libboost_filesystem.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/usr/lib/x86_64-linux-gnu/libboost_signals.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/opt/ros/kinetic/lib/librosconsole.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/opt/ros/kinetic/lib/librosconsole_log4cxx.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/opt/ros/kinetic/lib/librosconsole_backend_interface.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/usr/lib/x86_64-linux-gnu/liblog4cxx.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/usr/lib/x86_64-linux-gnu/libboost_regex.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/opt/ros/kinetic/lib/libxmlrpcpp.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/opt/ros/kinetic/lib/libroscpp_serialization.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/opt/ros/kinetic/lib/librostime.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/opt/ros/kinetic/lib/libcpp_common.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/usr/lib/x86_64-linux-gnu/libboost_system.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/usr/lib/x86_64-linux-gnu/libboost_thread.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/usr/lib/x86_64-linux-gnu/libboost_chrono.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/usr/lib/x86_64-linux-gnu/libboost_date_time.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/usr/lib/x86_64-linux-gnu/libboost_atomic.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/usr/lib/x86_64-linux-gnu/libpthread.so" to target "talker" which is not built in this directory.
CMake Error at ROS-Academy-for-Beginners-master/topic_demo/CMakeLists.txt:157 (target_link_libraries): Attempt to add link library "/usr/lib/x86_64-linux-gnu/libconsole_bridge.so" to target "talker" which is not built in this directory.