In /logs/firmware/unblob_extracted/firmware_extract/1568982-13971496.squashfs_v4_le_extract/etc/hotplug.d/iface/20-firewall line 3:

[ "$ACTION" = ifup -o "$ACTION" = ifupdate ] || exit 0

                   ^-- SC2166 (warning): Prefer [ p ] || [ q ] as [ p -o q ] is not well defined.

In /logs/firmware/unblob_extracted/firmware_extract/1568982-13971496.squashfs_v4_le_extract/etc/hotplug.d/iface/20-firewall line 4:

[ "$ACTION" = ifupdate -a -z "$IFUPDATE_ADDRESSES" -a -z "$IFUPDATE_DATA" ] && exit 0

                       ^-- SC2166 (warning): Prefer [ p ] && [ q ] as [ p -a q ] is not well defined.

                                                   ^-- SC2166 (warning): Prefer [ p ] && [ q ] as [ p -a q ] is not well defined.

For more information:

  https://www.shellcheck.net/wiki/SC2166 -- Prefer [ p ] && [ q ] as [ p -a q...