ros2运行rosdep update成功应该是什么样子

在ROS 2中，运行`rosdep update`命令成功后，会显示已经下载了最新的软件包元数据，并更新了本地缓存。如果没有错误信息，则表示更新成功，类似于下面的输出：

$ rosdep update
reading in sources list data from /etc/ros/rosdep/sources.list.d
Hit https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/osx-homebrew.yaml
Hit https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/base.yaml
Hit https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/python.yaml
Hit https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/ruby.yaml
Hit https://raw.githubusercontent.com/ros/rosdistro/master/releases/fuerte.yaml
Query rosdistro index for distro "noetic"
Added new distro entry: "noetic"
Query rosdistro index for distro "melodic"
Added new distro entry: "melodic"
Query rosdistro index for distro "kinetic"
Added new distro entry: "kinetic"
Updated rosdistro index
rosdep update successful

其中，`rosdep update successful`字样表示更新成功。