Replacing `--listen=127.0.0.1` to `--listen=localhost` solved our ipv6 resolution. We had a weird bug that when you passed localhost as the domain name of gearman, it would not work with --listen=127.0.0.1. This was weird (or not, i'm not the network guy) because our /etc/hosts file resolved localhost to both ipv4 127.0.0.1 and ipv6 ::1 address.
