Crash when loading IPv6 GeoIP database

I'm wanting to be able to geolocate IPv6 addresses. MaxMind publish a free (beta) IPv6 database along side their free IPv4 database, but when I configure it, logstash crashes during initialization. Has anyone gotten this to work?

[icb@n logstash-2.3.1]$ ./bin/logstash -f v6test.conf
Settings: Default pipeline workers: 1
Pipeline aborted due to error {:exception=>#<NameError: uninitialized constant LogStash::Filters::GeoIP::RuntimeException>, :backtrace=>["org/jruby/RubyModule.java:2745:in `const_missing'", "/home/icb/elastic/logstash-2.3.1/vendor/bundle/jruby/1.9/gems/logstash-filter-geoip-2.0.7/lib/logstash/filters/geoip.rb:114:in `register'", "/home/icb/elastic/logstash-2.3.1/vendor/bundle/jruby/1.9/gems/logstash-core-2.3.1-java/lib/logstash/pipeline.rb:182:in `start_workers'", "org/jruby/RubyArray.java:1613:in `each'", "/home/icb/elastic/logstash-2.3.1/vendor/bundle/jruby/1.9/gems/logstash-core-2.3.1-java/lib/logstash/pipeline.rb:182:in `start_workers'", "/home/icb/elastic/logstash-2.3.1/vendor/bundle/jruby/1.9/gems/logstash-core-2.3.1-java/lib/logstash/pipeline.rb:136:in `run'", "/home/icb/elastic/logstash-2.3.1/vendor/bundle/jruby/1.9/gems/logstash-core-2.3.1-java/lib/logstash/agent.rb:465:in `start_pipeline'"], :level=>:error}
stopping pipeline {:id=>"main"}
[icb@n logstash-2.3.1]$

Minimal config to reproduce this (with the GeoLite City IPv6 (Beta) database put at the geoip database path):

input {
	stdin {}
}
filter {
	grok {
		match => {
			"message" => "%{SYSLOGBASE} queries: info: client %{IP:clientip}#%{INT:port}: query: %{DATA:query} %{WORD:class} %{WORD:querytype} %{DATA:flags} \(%{IP:serverip}\)"
		}
	}
	geoip {
		database => "/home/icb/elastic/maxmind/GeoLiteCityv6.dat"
		source => "clientip"
	}
}
output {
	elasticsearch {}
}

I don't believe that LS filter handles IPv6 - https://github.com/logstash-plugins/logstash-filter-geoip/issues?utf8=✓&q=is%3Aissue+is%3Aopen+ipv6

Thanks. Looks like support was added in PR 64 (not yet released), but comments suggest that also dropped support for the ASN database.