Re: Prefer luatex for documentation

[Werner LEMBERG]

>> Luatex would be the final engine to support.
> 
> [...] I see no reason to assume that there won't be yet another
> engine (LuaTeX is already the fourth, if I count correctly),

Jonas, please don't think absolute, think *relative*!  If I say
'final', *of course* I mean the engines available today.  Everything
else would be silly.

> Once again, my question is: What is the plan here?

*My* plan is to provide the best typographical output for our
documentation.  As explained, this is only possible with luatex.

> What I'm asking about is what configure should look for
> automatically, which is implicitly the same as "what do we recommend
> using".

I no longer care.  It makes me too tired to defend my position.  If
you are happy with the XeTeX results, so be it.

>> However, on a practical level, the PDF outlines are bad with pdftex
>> if there are non-ASCII characters.  This is not a limitation of
>> pdftex but a limitation of `texinfo.tex`, which doesn't provide
>> support for that, unfortunately (someone™ could contribute this,
>> since the maintainer don't want to add it by himself).
> 
> If PDF outlines are really the only inferior thing about pdfTeX (and
> it already features full microtype support), then IMHO we should
> really just spend our time fixing that one issue instead of
> complicating our lives with multiple TeX engines...

Jean mentioned issue #6275 as a potential further improvement, which
is *definitely* not possible with pdftex.

>> For me it's fully ok if pdftex gets used for testing.  However, for
>> the generation of the PDF documentation that gets provided to the
>> user, luatex (or xetex) is preferable.
> 
> Yet, your merge request also uses LuaTeX during CI testing.  Which
> makes me wonder why this works without installing texlive-luatex?

Good question.  I was surprised by that, too.

> And whether we can just *require* LuaTeX and stop looking for pdfTeX
> and XeTeX altogether?

This is always possible.  Please decide by yourself.

>> I disagree with that conclusion, but if you feel that we really,
>> really must disable xetex support in favor of luatex, let's do it.
> 
> This is not what I'm saying. I have been asking what the plans are
> and stating that the incremental improvements I see with LuaTeX are
> not worth looking for and testing yet another engine.

I can only say: Compiling with luatex works now, as the pipelines
demonstrate.

> You keep saying that you want to support everything, which in my
> opinion is not sustainable, but are fine with dropping XeTeX which
> you only asked me to install for the documentation build less than a
> month ago?

Do you know the word 'compromise'?  At that point of time, XeTeX was
better than pdfTeX, and my request for luatex support wasn't ready
yet.

> To make a general remark here: Proposals are more convincing if they
> are made with a proper motivation following stable positions. Just
> changing mind every few weeks is a bad driver for change IMO.

My position is stable, but I don't have the stamina to argue again and
again and again.


    Werner