编译ORB_SLAM3的ROS部分报错

编译ORB_SLAM3的ROS部分的时候出现了如下的错误，一直不知道什么原因。

CMake Deprecation Warning at /opt/ros/melodic/share/ros/core/rosbuild/rosbuild.cmake:7 (cmake_policy):
  The OLD behavior for policy CMP0011 will be removed from a future version
  of CMake.

  The cmake-policies(7) manual explains that the OLD behaviors of all
  policies are deprecated and that a policy should be set to OLD only under
  specific short-term circumstances.  Projects should be ported to the NEW
  behavior and not rely on setting a policy to OLD.
Call Stack (most recent call first):
  CMakeLists.txt:2 (include)


CMake Deprecation Warning at /opt/ros/melodic/share/ros/core/rosbuild/rosbuild.cmake:16 (cmake_policy):
  The OLD behavior for policy CMP0002 will be removed from a future version
  of CMake.

  The cmake-policies(7) manual explains that the OLD behaviors of all
  policies are deprecated and that a policy should be set to OLD only under
  specific short-term circumstances.  Projects should be ported to the NEW
  behavior and not rely on setting a policy to OLD.
Call Stack (most recent call first):
  CMakeLists.txt:2 (include)


CMake Deprecation Warning at /opt/ros/melodic/share/ros/core/rosbuild/rosbuild.cmake:18 (cmake_policy):
  The OLD behavior for policy CMP0003 will be removed from a future version
  of CMake.

  The cmake-policies(7) manual explains that the OLD behaviors of all
  policies are deprecated and that a policy should be set to OLD only under
  specific short-term circumstances.  Projects should be ported to the NEW
  behavior and not rely on setting a policy to OLD.
Call Stack (most recent call first):
  CMakeLists.txt:2 (include)


CMake Deprecation Warning at /opt/ros/melodic/share/ros/core/rosbuild/rosbuild.cmake:20 (cmake_policy):
  The OLD behavior for policy CMP0005 will be removed from a future version
  of CMake.

  The cmake-policies(7) manual explains that the OLD behaviors of all
  policies are deprecated and that a policy should be set to OLD only under
  specific short-term circumstances.  Projects should be ported to the NEW
  behavior and not rely on setting a policy to OLD.
Call Stack (most recent call first):
  CMakeLists.txt:2 (include)


CMake Deprecation Warning at /opt/ros/melodic/share/ros/core/rosbuild/rosbuild.cmake:23 (cmake_policy):
  The OLD behavior for policy CMP0011 will be removed from a future version
  of CMake.

  The cmake-policies(7) manual explains that the OLD behaviors of all
  policies are deprecated and that a policy should be set to OLD only under
  specific short-term circumstances.  Projects should be ported to the NEW
  behavior and not rely on setting a policy to OLD.
Call Stack (most recent call first):
  CMakeLists.txt:2 (include)


[rosbuild] Building package ORB_SLAM3
Failed to invoke /opt/ros/melodic/bin/rospack deps-manifests ORB_SLAM3
[rospack] Error: the rosdep view is empty: call 'sudo rosdep init' and 'rosdep update'


CMake Error at /opt/ros/melodic/share/ros/core/rosbuild/public.cmake:129 (message):
  

  Failed to invoke rospack to get compile flags for package 'ORB_SLAM3'.
  Look above for errors from rospack itself.  Aborting.  Please fix the
  broken dependency!

Call Stack (most recent call first):
  /opt/ros/melodic/share/ros/core/rosbuild/public.cmake:207 (rosbuild_invoke_rospack)
  CMakeLists.txt:4 (rosbuild_init)


-- Configuring incomplete, errors occurred!
See also "/home/gyp/ORB_SLAM3_origin/Examples_old/ROS/ORB_SLAM3/build/CMakeFiles/CMakeOutput.log".

后来仔细看了错误提示，发现是因为ros安装的原因。我是使用一键安装ROS，其中sudo rosdep init和rosdep update没有成功，以为没有影响，结果还是有影响。

解决方法：
把sudo rosdep init和rosdep update执行成功就可以了，下次编译就没有问题了。