Connecting via IPv6 fails

[ghost]

IPv6 host

18:19:09.565 [error] GenServer MathLogicTest terminating
** (CaseClauseError) no case clause matching: {:error, :nxdomain}
    (rethinkdb 0.4.0) lib/rethinkdb/connection.ex:261: RethinkDB.Connection.connect/2
    (connection 1.0.4) lib/connection.ex:622: Connection.enter_connect/5
    (stdlib 3.13) proc_lib.erl:226: :proc_lib.init_p_do_apply/3
Last message: nil
State: %{config: %{auth_key: "", host: '2a03:b0c0:3:d0::b7:c001', max_pending: 10000, port: 28015, transport: {%RethinkDB.Connection.Transport.TCP{socket: nil}, []}}, current: {:start, ""}, pending: %{}, token: 0}

-> Must not connect but catch wrong IPv6 address format

IPv6 host with [] address

19:34:13.057 [error] GenServer MathLogicTest terminating
** (CaseClauseError) no case clause matching: {:error, :nxdomain}
    (rethinkdb 0.4.2) lib/rethinkdb/connection.ex:261: RethinkDB.Connection.connect/2
    (connection 1.0.4) lib/connection.ex:622: Connection.enter_connect/5
    (stdlib 3.13) proc_lib.erl:226: :proc_lib.init_p_do_apply/3
Last message: nil
State: %{config: %{auth_key: "", host: '[fe80::4f0:2fac:73c9:6b84]', max_pending: 10000, port: 28015, transport: {%RethinkDB.Connection.Transport.TCP{socket: nil}, []}}, current: {:start, ""}, pending: %{}, token: 0}
-> Must connect

  0) MathLogicTest: failure on setup_all callback, all tests have been invalidated
     ** (EXIT from #PID<0.435.0>) an exception was raised:
         ** (CaseClauseError) no case clause matching: {:error, :nxdomain}
             (rethinkdb 0.4.2) lib/rethinkdb/connection.ex:261: RethinkDB.Connection.connect/2
             (connection 1.0.4) lib/connection.ex:622: Connection.enter_connect/5
             (stdlib 3.13) proc_lib.erl:226: :proc_lib.init_p_do_apply/3

Connecting to a temporary DigitalOcean droplet using IPv6 address fails.