Comment 2 for bug 1966886

the problem is in this file https://github.com/openssh/openssh-portable/blob/master/contrib/ssh-
copy-id

in line 335

dropbear*)
    populate_new_ids 0
    [ "$DRY_RUN" ] || printf '%s\n' "$NEW_IDS" | \
      $SSH "$@" "$(installkeys_sh /etc/dropbear/authorized_keys)" \
      || exit 1
    ADDED=$(printf '%s\n' "$NEW_IDS" | wc -l)
    ;;

dropbear only uses the file /etc/dropbear/authorized_keys if it was patched
in the upstream version of dropbear the patch is not included

im working with some embedded systems where the file /etc/dropbear/authorized_keys is not writeable

with older ubuntu systems ssh-copy-id was working
but since that change in ssh-copy-id can't install the ssh key anymore