one,
Type in terminal:
sudo apt update
or
sudo apt-get update
Error message :
Get: 1 http://mirrors.ustc.edu.cn/kali kali-rolling InRelease [30.6 kB]
Error: 1 http://mirrors.ustc.edu.cn/kali kali-rolling
InRelease key, the following signatures could not be verified: NO_PUBKEY ED444FF07D8D0BF6
Ignored: 2 http://mirrors.tuna.tsinghua.edu.cn/ros/ubuntu xenial InRelease
Hit: 3 http://mirrors.tuna.tsinghua.edu.cn/ros/ ubuntu xenial Release
reading package list... done
N: ignoring 'ros-latest.list122' (in directory '/etc/apt/sources.list.d/') given its invalid file extension
W: GPG error : http://mirrors.ustc.edu.cn/kali kali-rolling InRelease: The following signature cannot be verified because there is no public key: NO_PUBKEY ED444FF07D8D0BF6
E: Warehouse "http://mirrors.ustc.edu.cn/kali kali- rolling InRelease" without a digital signature.
N: The source cannot be safely updated, so it is disabled by default.
N: See the apt-secure(8) manual for details on repository creation and user configuration.
As shown in the picture:
Solution:
1. Find the software and update
2. Remove the check mark in front of the wrong URL in "Other Software"
3. Save the settings, and then enter again
sudo apt update
or
sudo apt-get update
can be solved.
two,
Type in terminal:
sudo apt install ros-melodic-desktop-full
Error message:
[sudo] password for amanda:
Reading package list... Done
Analyzing package dependency tree
Reading status information... Done
N: Ignoring 'ros-latest.list122' (in directory '/etc/ apt/sources.list.d/'), given its file extension is invalid
E: Unable to locate package ros-melodic-desktop-full
As shown in the picture:
Solution:
The ubuntu version does not correspond to the ros version. I use Ubuntu16.04, and the corresponding version should be kinetic.
Change to:
sudo apt install ros-kinetic-desktop-full
In addition: Ubuntu18.04 corresponds to melodic
Ubuntu20.04 corresponds to Noetic
three,
Type in terminal:
source ~/.bashrc
Error message:
bash: /opt/ros/melodic/setup.bash: No such file or directory
As shown in the picture:
This error is so rampant that even if it is not executed, it will appear as long as the terminal is opened:
Reason:
Forgot to change the ros version when executing the command: echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc
Solution:
1. Enter in the terminal:
gedit ~/.bashrc
2. Find /opt/ros/melodic/setup.bash in the error message in the opened file, delete this line, save and exit.
Execute the command again after changing the ros version:
echo "source /opt/ros/kinetic/setup.bash" >> ~/.bashrc
source ~/.bashrc
The error disappears.
Four,
Type in terminal:
sudo rosdep init
错误提示：
Traceback (most recent call last):
File “/usr/bin/rosdep”, line 6, in
from pkg_resources import load_entry_point
File “/usr/lib/python2.7/dist-packages/pkg_resources/init.py”, line 2927, in
@_call_aside
File “/usr/lib/python2.7/dist-packages/pkg_resources/init.py”, line 2913, in _call_aside
f(*args, **kwargs)
File “/usr/lib/python2.7/dist-packages/pkg_resources/init.py”, line 2940, in _initialize_master_working_set
working_set = WorkingSet._build_master()
File “/usr/lib/python2.7/dist-packages/pkg_resources/init.py”, line 637, in _build_master
return cls._build_from_requirements(requires)
File “/usr/lib/python2.7/dist-packages/pkg_resources/init.py”, line 650, in _build_from_requirements
dists = ws.resolve(reqs, Environment())
File “/usr/lib/python2.7/dist-packages/pkg_resources/init.py”, line 829, in resolve
raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The ‘rospkg>=1.3.0’ distribution was not found and is required by rosdep
As shown in the picture:
Solution:
1. Install pip first:
sudo apt-get install python-pip
2. Then use pip to install rosdep
sudo pip install rosdep
3. Initialize again:
sudo rosdep init
solve.
five,
Type in terminal:
sudo rosdep init
错误提示：
ERROR: default sources list file already exists:
/etc/ros/rosdep/sources.list.d/20-default.list
Please delete if you wish to re-initialize
As shown in the picture:
Solution:
The extension is invalid, remove it
sudo rm /etc/ros/rosdep/sources.list.d/20-default.list
Execute again:
sudo rosdep init
error disappears
This method also solves the error message:
N: Ignoring 'ros-latest.list122' (in directory '/etc/apt/sources.list.d/'), given its invalid file extension
six,
Type in terminal:
roscore
Red warning:
WARNING: ROS_MASTER_URI [http://192.168.43.157:11311] host is not set to this machine
As shown in the picture:
Solution: first press Ctrl+C to exit
1, enter in the terminal
ifconfig
2. Open the bashrc file
gedit ~/.bashrc
3. Find ROS_MASTER_URI=http://192.168.*****:11311 and change it to your own address
4. Source the environment variable
source ~/.bashrc
5. Execute again
roscore
The red warning disappears.
A little thought : This is just a small part of a lot of pitfalls stepped on when installing ros. During the actual installation, I also encountered a series of other problems such as blocked overseas resources and unable to download. I almost started from getting started. to buried. But for most of the problems, there are very detailed solutions on the Internet. These are some of the problems I encountered that I still remember. for reference only!