Warnings from asciidoc

[Matthew Selsky]

Hi,

Let me clear up two things:
- The project doesn't build docs by default (https://gitlab.com/NTPsec/ntpsec/blob/master/wafhelpers/options.py#L90).  You must specify "--enable-doc" to "waf configure".
- Our CI doesn't attempt to build documentation for all targets in an effort to make sure each CI pipeline doesn't take so long that developers are encouraged to side-step it. We build docs only in the "pages" pipeline.  See https://gitlab.com/NTPsec/ntpsec/blob/master/.gitlab-ci.yml#L1  We build using an Alpine image since it's super small and fast to prepare, compared to other distros.

The underlying problem that Hal saw was first reported upstream at https://github.com/asciidoc/asciidoc-py3/issues/13, and a fix was committed upstream at https://github.com/asciidoc/asciidoc-py3/pull/14  It was previously reported on this list by Udo at https://lists.ntpsec.org/pipermail/devel/2018-October/006703.html  The last message in that thread was https://lists.ntpsec.org/pipermail/devel/2018-October/006706.html.

I've filed https://bugzilla.redhat.com/show_bug.cgi?id=1655337 so that Fedora can fix their package.

We could build docs in every target, but warnings from asciidoc won't fail any builds since asciidoc still returns a zero exit code and we wouldn't notice the warnings unless someone specifically looked.  These warnings don't impact the html, etc, generated by asciidoc.  They're just ugly.

asciidoc-py3 still reports as 8.6.10 so there's little that we can check and warn the user about during our waf configure/build steps.  Unless we want to hardcode a check for F29 and emit a warning...

So I don't think our project needs to do anything.

I've filed https://gitlab.com/NTPsec/ntpsec/issues/521 so that we can track upstream progress and have something to point users to.


Thanks,
-Matt