python-rosdep-modules : 依赖: python-rosdistro-modules (>= 0.7.5) 但是它将不会被安装 E: Sub-process /usr/ ...

ros下跑小乌龟的时候出现了这个问题 rosrun turtlesim turtle_teleop_key 　　报错 rospack:command not found ...

ERROR: cannot download default sources list from: https://raw.githubusercontent.com/ros/rosdistro ...