As of the 1.0.0 release, we have two known issues. Both are related to the
underlying ldns library, and should be automatically fixed with the ldns
release following the currently latest 1.6.17.

1. Test Delegation/delegation03 is unreliable.
    
    This test checks that the smallest possible valid referral packet for a
    domain fits in a non-EDNS0 512-octet UDP packet. It does this by assembling
    the information that must be included, adding it to a packet and then
    checking the size of the resulting packet. Since ldns 1.6.17 and earlier
    does not do name compression in outgoing packets, this test will quite
    often report that packets are too big when in reality they are not.

2. Test Nameserver/nameserver03 can hang.
    
    When doing zone transfers, ldns only applies a timeout to the initial TCP
    connection establishment. If a name server sets up the connection
    correctly, but then neither completes the transfer nor drops the
    connection, ldns will wait forever for the transfer to finish. We have
    unfortunately seen this behavior on a small number of servers in the wild.

