I think fail2ban uses whois internally when it reports, but the ebuild doesnt have net-misc/whois as dependency Reproducible: Always
it's in 0.8.3 too: %% grep -r "/usr/bin/whois" * fail2ban-0.8.3/config/action.d/sendmail-whois.conf: `/usr/bin/whois <ip>`\n fail2ban-0.8.3/config/action.d/sendmail-whois-lines.conf: `/usr/bin/whois <ip>`\n\n fail2ban-0.8.4/config/action.d/sendmail-whois-lines.conf: `/usr/bin/whois <ip>`\n\n fail2ban-0.8.4/config/action.d/sendmail-whois.conf: `/usr/bin/whois <ip>`\n fixed in 0.8.4, thanks.