Re: meson documentation build open issues

On 09.11.23 18:52, Andres Freund wrote:
>> Besides giving you a quick validity check of the XML, this also builds the
>> doc_generated, which draw from non-doc source files, so this would also
>> serve to check that those are sound and didn't mess up the docs.
> Unfortunately presence of xmllint doesn't guarantee presence of the relevant
> DTDs. Without docbook-xml installed, you'll get something like
> 
> ../../../../../home/andres/src/postgresql/doc/src/sgml/postgres.sgml:21: warning: failed to load external
entity"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd"
> ]>
>    ^
> 
> and a bunch of other subsequent errors.
> 
> 
> I think if we want to do this, we'd need a configure time check for being able
> to validate a document with
> <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML
V4.5//EN""http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd"...

We used to have exactly such a check in configure, but it was removed in 
4823c4f6ac.  I suppose we could look into reviving that.