In /usr/bin/manpage-alert line 103:
    if [ -L /bin -a -L /sbin ]; then
                 ^-- SC2166: 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...