I am working on Unitree A1 Quadruped Robot. The bot has two boards, with Raspberry Pi on the front board. I am trying to install the ROS Melodic Raspberry Pi version using this link:

When I run the sudo apt-key adv --keyserver hkp://ha.pool.sks-keyservers.net:80 --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654, I get an error keyserver receive failed. Below is the complete error:

E: The repository ‘http://archive.ubuntu.com/ubuntu bionic InRelease' is not signed.
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.

pi@raspberrypi:~$ sudo apt-key adv --keyserver hkp://ha.pool.sks-keyservers.net:80 --recv-key C1CF6E31E6BADE88686172B4F 42ED6FBAB17C654
Executing: /tmp/apt-key-gpghome.D3A4dBRePX/gpg.1.sh --keyserver hkp://ha.pool.sks-keyservers.net:86 --recv-key C1CF6E31E6BADE8868B172B4F 42ED6FBAB17C654
gpg: keyserver receive failed: Server indicated a failure

Later, upon continuing the installation, I got errors installing the catkin workspace. How can I proceed with installing ROS?


1 Answer 1


The key server infrastructure is sometimes not working. You can try again later, or use alternative pools.

However, in general we have moved to recommending getting the keys from GitHub via curl

curl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | sudo apt-key add -

The latest official instructions are linked below. I recommend following those for setting up your keys as the instructions here may go out of date.


Note that I've linked to noetic as it's still supported. Melodic is EOL so things will get further and further out of date over time.


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