###### tags: `troubleshooting` [TOC] # Common Troubleshooting ### SSH ::: warning WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! ::: ```$ ssh-keygen -R <trouble_IP>``` ### cakin_make problem ::: warning ``` =bash CMake Error at /usr/share/cmake-3.13/Modules/FindPackageHandleStandardArgs.cmake:137 (message): Could NOT find PythonInterp: Found unsuitable version "1.4", but required is at least "2" (found /home/pi2/test_catkin_ws/build/python3) Call Stack (most recent call first): /usr/share/cmake-3.13/Modules/FindPackageHandleStandardArgs.cmake:376 (_FPHSA_FAILURE_MESSAGE) /usr/share/cmake-3.13/Modules/FindPythonInterp.cmake:159 (FIND_PACKAGE_HANDLE_STANDARD_ARGS) /opt/ros/melodic/share/catkin/cmake/python.cmake:4 (find_package) /opt/ros/melodic/share/catkin/cmake/all.cmake:164 (include) /opt/ros/melodic/share/catkin/cmake/catkinConfig.cmake:20 (include) CMakeLists.txt:56 (find_package) -- Configuring incomplete, errors occurred! See also "/home/pi2/test_catkin_ws/build/CMakeFiles/CMakeOutput.log". Invoking "cmake" failed ``` ::: 1. 將 workspace 底下的 `devel` `build` 資料夾刪掉 2. 用`catkin_make` 別用 `catkin_make -DPYTHON_EXECUTABLE=python3` ### ROS 互相連線連不上 #### 確保連到同一個網域底下 1. IP 可以透過輸入 ifconfig 去查看 2. 同網域代表開頭都會是 192.168.X.X 3. 也可以嘗試去終端機輸入 ``` $ ping 別人的IP``` 看看收不收的到 #### 修改環境變數 1. ```$ vim ~/.bashrc``` 2. **到最下面加上這三句** ``` $ export ROS_MASTER_URI=http:// **有開roscore電腦的IP**:11311 $ export ROS_HOSTNAME=**自己的IP** $ export ROS_IP=**自己的IP** ```