Сборка ISO не принимает системные имена администратора (admin, root, kvm): установщик Ubuntu их отвергает, и автоматическая установка падала на первом шаге

image/build-iso.sh

@@ -106,6 +106,7 @@ esac
 [[ "$WEB_PORT" =~ ^[0-9]+$ ]] && (( WEB_PORT >= 1 && WEB_PORT <= 65535 )) || die "invalid --web-port: $WEB_PORT"
 if [[ "$UNATTENDED" == "1" ]]; then
   [[ "$USERNAME" =~ ^[a-z_][a-z0-9_-]{0,31}$ ]] || die "--unattended needs a valid --username"
+  ! grep -qxF "$USERNAME" "${IMAGE_DIR}/reserved-usernames" || die "--username ${USERNAME} is reserved by the Ubuntu installer (like admin, root, kvm); pick another name"
   [[ "$PASSWORD_HASH" == \$* ]] || die "--unattended needs --password-hash (generate: openssl passwd -6)"
   [[ "$HOSTNAME_VALUE" =~ ^[a-zA-Z0-9][a-zA-Z0-9-]{0,62}$ ]] || die "invalid --hostname"
 fi