I am trying to create a Ros Workspace on my nvidia nano jetson. It has ubuntu version 18.04.
I want to install ros-melodic but i recieve the following error message.

Error message:
The following packages have unmet dependencies:
ros-melodic-desktop-full : Depends: ros-melodic-desktop but it is not going to be installed
Depends: ros-melodic-perception but it is not going to be installed
Depends: ros-melodic-simulators but it is not going to be installed
Depends: ros-melodic-urdf-sim-tutorial but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
cian@cian-desktop:~$ Unable to correct problems, you have held broken packages.

Has anybody had this problem before and do they know how to solve it?

Kind regards

I have tried to following commands without succes:
List of commands:
1.
sudo sh -c ‘echo “deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main” > /etc/apt/sources.list.d/ros-latest.list’
sudo apt install curl
curl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | sudo apt-key add –
sudo apt update
sudo apt install ros-melodic-desktop-full

2.
sudo apt-get update
sudo apt-get upgrade

3.
sudo apt install gazebo9-common libgazebo9-dev gazebo9 ros-melodic-gazebo-ros-pkgs ros-melodic-gazebo-dev ros-melodic-gazebo-ros-control ros-melodic-gazebo-ros ros-melodic-urdf-sim-tutorial ros-melodic-simulators
sudo apt-get install ros-melodic-desktop-full