It may be a problem if you use Husarnet, but the fix is simple, the following is just a snip from my robot build procedure.
If during apt update an error is encountered relating to ‘husarnet signature needs updating’ do the following:
To update the key/signature:
i. su root (The following command needs to be run as root)
ii. curl https://install.husarnet.com/key.asc | apt-key add -
iii. ctrl d to revert to husarion prompt (The following command should’t be run as root)
iv. sudo apt update
The information relating to the above can be found here: