Update LDNS submodule to v1.8.4

[MichaelTimbert]

Purpose

Update LDNS submodule to 1.8.4

Context

Close #194

[matsduf]

Travis does not like this for some reason.

[marc-vanderwal]

That’s because running autoreconf -fi on LDNS’s source tree errors out with:

configure.ac:3: error: Autoconf version 2.71 or higher is required

The OS used for CI is Ubuntu 20.04 LTS (focal), which provides autoconf version 2.69. Too bad :(

[marc-vanderwal]

It won’t be easy to fix. I don’t think Ubuntu 20.04 is likely to provide a newer autoconf in its package repositories. On the other hand, autoconf 2.71 fixes lots of bugs but has backwards compatibility issues, so I don’t know if we can reasonably expect ldns to lower its requirement of autoconf.

For CI, the easiest fix is to test with a later version of Ubuntu. Regardless of how we proceed to fix CI, we’ll have to document that Ubuntu 20.04 users must install ldns separately, then install Zonemaster::LDNS with --no-internal-ldns.

[matsduf]

For CI, the easiest fix is to test with a later version of Ubuntu. Regardless of how we proceed to fix CI, we’ll have to document that Ubuntu 20.04 users must install ldns separately, then install Zonemaster::LDNS with --no-internal-ldns.

But only if we decide to upgrade LDNS to 1.8.4, right? As far as I can see, only LDNS 1.7.0 is available for Ubuntu 20.04. That could mean that we have to drop Ubuntu 20.04 already for v2024.2 instead of for v2025.1. Maybe that is OK.

[marc-vanderwal]

Alternatively, we could wait until we are working on v2025.1 before merging.

[matsduf]

Yes, I support waiting until v2025.1 or even v2025.2.