Yeah, you can always compile it, but bins are available now for Debian-based distros, CentOS and Fedora.
https://community.openvpn.net/openvpn/wiki/OpenvpnSoftwareRepos#Usingrepos.openvpn.net
You need to specify one subnet (a /112 at least IIRC) using the server-ipv6 directive and set net.ipv6.conf.all.forwarding=1 at sysctl if you want your clients to reach the IPv6 Internet.
Now, I suppose we need more low end providers giving small IPv6 subnets and not a bunch of random addresses ;)