我正试图使用wiki.ROS.org上的说明安装ROS Melodic，但遇到了一些问题。
系统软件信息：
操作系统：Kubuntu 21.10
KDE Plasma版本：5.22.5
KDE框架版本：5.86.0
Qt版本：5.15.2
内核版本：5.13.0-19-通用(64位(
图形平台：X11
问题
我首先从http://wiki.ros.org/melodic/Installation/Ubuntu然后按照https://varhowto.com/install-ros-melodic-ubuntu-18-04/#Step_1_%E2%80%94_Install_ROS_Melodic_repo，均未成功。
当运行sudo apt update时，我得到：
Hit:1 http://archive.ubuntu.com/ubuntu impish InRelease
Get:2 http://archive.ubuntu.com/ubuntu impish-updates InRelease [110 kB]
Ign:3 http://packages.ros.org/ros/ubuntu impish InRelease
Get:4 http://archive.ubuntu.com/ubuntu impish-backports InRelease [101 kB]
Hit:5 http://packages.ros.org/ros/ubuntu bionic InRelease
Get:6 http://archive.ubuntu.com/ubuntu impish-security InRelease [110 kB]
Err:7 http://packages.ros.org/ros/ubuntu impish Release
404 Not Found [IP: 140.211.166.134 80]
Reading package lists... Done
E: The repository 'http://packages.ros.org/ros/ubuntu impish Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
尝试用这条线安装后：
sudo apt install ros-melodic-desktop-full
我得到：
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Selected version '1.4.1-0bionic.20211104.025752' (ROS bionic:bionic [amd64]) for 'ros-melodic-desktop-full'
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies.
python-rospkg : Depends: python-yaml but it is not installable
python-rospkg-modules : Depends: python-yaml but it is not installable
Depends: python-catkin-pkg-modules but it is not going to be installed
ros-melodic-actionlib : Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
ros-melodic-actionlib-tutorials : Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
ros-melodic-bondcpp : Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
ros-melodic-camera-calibration-parsers : Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-python1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libyaml-cpp0.5v5 but it is not installable
ros-melodic-camera-info-manager : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-catkin : Depends: python-catkin-pkg (> 0.4.3) but it is not going to be installed
Depends: python-empy but it is not installable
Depends: python-nose but it is not installable
ros-melodic-class-loader : Depends: libboost-system1.65.1 but it is not installable
Depends: libpocofoundation50 but it is not installable
ros-melodic-compressed-depth-image-transport : Depends: libboost-system1.65.1 but it is not installable
Depends: libopencv-core3.2 but it is not installable
Depends: libopencv-imgcodecs3.2 but it is not installable
ros-melodic-compressed-image-transport : Depends: libboost-system1.65.1 but it is not installable
Depends: libopencv-core3.2 but it is not installable
Depends: libopencv-imgcodecs3.2 but it is not installable
Depends: libopencv-imgproc3.2 but it is not installable
ros-melodic-controller-manager : Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libtinyxml2-6 (>= 5.0.0) but it is not installable
ros-melodic-cv-bridge : Depends: libboost-python1.65.1 but it is not installable
Depends: libboost-regex1.65.1 but it is not installable
Depends: libopencv-core3.2 but it is not installable
Depends: libopencv-imgcodecs3.2 but it is not installable
Depends: libopencv-imgproc3.2 but it is not installable
Depends: python-opencv but it is not installable
ros-melodic-depth-image-proc : Depends: libboost-system1.65.1 but it is not installable
Depends: libopencv-core3.2 but it is not installable
Depends: libopencv-imgproc3.2 but it is not installable
ros-melodic-diagnostic-aggregator : Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-regex1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libtinyxml2-6 (>= 5.0.0) but it is not installable
ros-melodic-diagnostic-common-diagnostics : Depends: python-psutil but it is not installable
ros-melodic-diff-drive-controller : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-dynamic-reconfigure : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-filters : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-gazebo-plugins : Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
Depends: libgazebo9 but it is not going to be installed
Depends: libignition-common but it is not installable
Depends: libignition-math4 but it is not installable
Depends: libopencv-core3.2 but it is not installable
Depends: libopencv-imgproc3.2 but it is not installable
Depends: libprotobuf10 but it is not installable
Depends: libsdformat6 but it is not installable
ros-melodic-gazebo-ros : Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
Depends: libgazebo9 but it is not going to be installed
Depends: libignition-common but it is not installable
Depends: libprotobuf10 but it is not installable
Depends: libsdformat6 but it is not installable
ros-melodic-gazebo-ros-control : Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
Depends: libgazebo9 but it is not going to be installed
Depends: libignition-common but it is not installable
Depends: libignition-math4 but it is not installable
Depends: libsdformat6 but it is not installable
Depends: libtinyxml2-6 (>= 5.0.0) but it is not installable
Depends: ros-melodic-control-toolbox but it is not going to be installed
Depends: ros-melodic-transmission-interface but it is not going to be installed
ros-melodic-genmsg : Depends: python-empy but it is not installable
ros-melodic-genpy : Depends: python-yaml but it is not installable
ros-melodic-image-geometry : Depends: libopencv-calib3d3.2 but it is not installable
Depends: libopencv-core3.2 but it is not installable
Depends: libopencv-imgproc3.2 but it is not installable
ros-melodic-image-proc : Depends: libboost-system1.65.1 but it is not installable
Depends: libopencv-core3.2 but it is not installable
Depends: libopencv-imgproc3.2 but it is not installable
ros-melodic-image-publisher : Depends: libboost-system1.65.1 but it is not installable
Depends: libopencv-core3.2 but it is not installable
Depends: libopencv-imgcodecs3.2 but it is not installable
Depends: libopencv-videoio3.2 but it is not installable
ros-melodic-image-rotate : Depends: libboost-system1.65.1 but it is not installable
Depends: libopencv-core3.2 but it is not installable
Depends: libopencv-imgproc3.2 but it is not installable
ros-melodic-image-transport : Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libtinyxml2-6 (>= 5.0.0) but it is not installable
ros-melodic-image-view : Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
Depends: libopencv-core3.2 but it is not installable
Depends: libopencv-highgui3.2 but it is not installable
Depends: libopencv-imgcodecs3.2 but it is not installable
Depends: libopencv-videoio3.2 but it is not installable
ros-melodic-interactive-marker-tutorials : Depends: libboost-system1.65.1 but it is not installable
Depends: ros-melodic-interactive-markers but it is not going to be installed
ros-melodic-joint-state-controller : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-kdl-parser : Depends: libtinyxml2-6 (>= 5.0.0) but it is not installable
ros-melodic-laser-assembler : Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libtinyxml2-6 (>= 5.0.0) but it is not installable
ros-melodic-laser-filters : Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libtinyxml2-6 (>= 5.0.0) but it is not installable
ros-melodic-laser-geometry : Depends: libboost-system1.65.1 but it is not installable
Depends: python-numpy but it is not installable
ros-melodic-librviz-tutorial : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-nodelet : Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
Depends: libtinyxml2-6 (>= 5.0.0) but it is not installable
ros-melodic-nodelet-tutorial-math : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-pcl-ros : Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libpcl-common1.8 but it is not installable
Depends: libpcl-features1.8 but it is not installable
Depends: libpcl-filters1.8 but it is not installable
Depends: libpcl-io1.8 but it is not installable
Depends: libpcl-search1.8 but it is not installable
Depends: libpcl-segmentation1.8 but it is not installable
Depends: libpcl-surface1.8 but it is not installable
ros-melodic-pluginlib-tutorials : Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libtinyxml2-6 (>= 5.0.0) but it is not installable
ros-melodic-position-controllers : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-python-orocos-kdl : Depends: python-sip-dev but it is not installable
ros-melodic-python-qt-binding : Depends: python-pyqt5 but it is not installable
Depends: python-pyqt5.qtsvg but it is not installable
Depends: python-sip-dev but it is not installable
ros-melodic-qt-dotgraph : Depends: python-pydot but it is not installable
ros-melodic-robot-state-publisher : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-rosbag : Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-program-options1.65.1 but it is not installable
Depends: libboost-regex1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
Depends: python-gnupg but it is not installable
Depends: python-pycryptodome but it is not installable
Depends: ros-melodic-rosbag-storage but it is not going to be installed
ros-melodic-rosconsole : Depends: libboost-regex1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: liblog4cxx10v5 (>= 0.10.0) but it is not installable
ros-melodic-roscpp : Depends: libboost-chrono1.65.1 but it is not installable
Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
ros-melodic-roscpp-tutorials : Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
ros-melodic-rosgraph : Depends: python-netifaces but it is not installable
Depends: python-yaml but it is not installable
ros-melodic-roslaunch : Depends: python-paramiko but it is not installable
Depends: python-yaml but it is not installable
ros-melodic-roslib : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-rosmaster : Depends: python-defusedxml but it is not installable
ros-melodic-rospack : Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-program-options1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libtinyxml2-6 (>= 5.0.0) but it is not installable
Depends: python-catkin-pkg-modules but it is not going to be installed
Depends: python-rosdep-modules but it is not going to be installed
ros-melodic-rosparam : Depends: python-yaml but it is not installable
ros-melodic-rospy : Depends: python-numpy but it is not installable
Depends: python-yaml but it is not installable
ros-melodic-rostime : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-roswtf : Depends: python-paramiko but it is not installable
ros-melodic-rqt-bag-plugins : Depends: python-cairo but it is not installable
Depends: python-pil but it is not installable
ros-melodic-rqt-image-view : Depends: libboost-system1.65.1 but it is not installable
Depends: libopencv-core3.2 but it is not installable
Depends: libopencv-imgproc3.2 but it is not installable
Depends: ros-melodic-rqt-gui-cpp but it is not going to be installed
ros-melodic-rqt-plot : Depends: python-matplotlib but it is not installable
Depends: python-numpy but it is not installable
ros-melodic-rqt-pose-view : Depends: python-opengl but it is not installable
Depends: ros-melodic-gl-dependency but it is not going to be installed
ros-melodic-rqt-reconfigure : Depends: python-yaml but it is not installable
ros-melodic-rqt-rviz : Depends: libboost-program-options1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: ros-melodic-rqt-gui-cpp but it is not going to be installed
ros-melodic-rqt-top : Depends: python-psutil but it is not installable
ros-melodic-rviz : Depends: libassimp4 but it is not installable
Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-program-options1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
Depends: libtinyxml2-6 (>= 5.0.0) but it is not installable
Depends: libyaml-cpp0.5v5 but it is not installable
Depends: ros-melodic-interactive-markers but it is not going to be installed
Depends: ros-melodic-resource-retriever but it is not going to be installed
ros-melodic-rviz-plugin-tutorials : Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
ros-melodic-self-test : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-stage-ros : Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
ros-melodic-stereo-image-proc : Depends: libboost-system1.65.1 but it is not installable
Depends: libopencv-calib3d3.2 but it is not installable
Depends: libopencv-core3.2 but it is not installable
ros-melodic-tf : Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
ros-melodic-tf2 : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-tf2-ros : Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
Depends: ros-melodic-tf2-py but it is not going to be installed
ros-melodic-theora-image-transport : Depends: libboost-system1.65.1 but it is not installable
Depends: libopencv-core3.2 but it is not installable
Depends: libopencv-imgproc3.2 but it is not installable
ros-melodic-turtle-actionlib : Depends: libboost-system1.65.1 but it is not installable
Depends: libboost-thread1.65.1 but it is not installable
ros-melodic-turtle-tf : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-turtle-tf2 : Depends: libboost-system1.65.1 but it is not installable
ros-melodic-urdf : Depends: libboost-filesystem1.65.1 but it is not installable
Depends: libboost-system1.65.1 but it is not installable
Depends: libtinyxml2-6 (>= 5.0.0) but it is not installable
ros-melodic-urdfdom-py : Depends: python-yaml but it is not installable
ros-melodic-webkit-dependency : Depends: python-pyqt5.qtwebkit but it is not installable
E: Unable to correct problems, you have held broken packages.
我试着把注意力集中在错误上
E: Unable to correct problems, you have held broken packages.
但从未找到安装ROS的解决方案。我使用Synaptic软件包管理器来修复和删除任何损坏的软件包，并试图解开每个软件包以解决问题，但没有任何效果。
有人知道怎么解决这个问题吗？非常感谢。
您收到这个错误是因为Melodic是Ubuntu 18.04的ros发行版。截至目前，最新发布的是Noetic，目标是20.04。你使用的Ubuntu版本目前没有支持的ROS版本，因此，如果你想要ROS，你唯一真正的选择就是降级。