I should really remember this as I have to use it often. Posting it here in the hope that it will stick eventually. I guess using it all the while instead of ssh-copy-id would do the trick.
$ cat ~/.ssh/id_ed25519.pub | ssh vincent@vlara.co.uk "mkdir -p ~/.ssh && \
cat >> ~/.ssh/authorized_keys"
I am not entirely certain what the cause of this error is but it is particularly annoying when it happens on a headless system.
I think that the problem is caused by too many keys to choose from during key negotiation, or no key at all. I found this workaround.
ssh -o PubkeyAuthentication=no vince@host
Once a successful login with a password is possible, logout and copy the authentication key to the host…
ssh-copy-id -o PubkeyAuthentication=no vince@host
Then login with ssh again…
ssh vince@host
And ssh should authenticate without using a password.
This is super easy, just press the ‘Windows’ key (flag) and the ‘Full Stop’ key (.) on your keyboard at the same time to pop-up the emoji selector.
After all these years, I just found this feature! It was mentioned in a VSCode YouTube tutorial that I watched yesterday.