# [luatex] Confirm change in TL 2016-pretest vs. TL 2015 behavior: dvilualatex fails because of pdfpageheight

Scott Kostyshak skostysh at lyx.org
Tue May 17 19:25:51 CEST 2016

```On Tue, May 17, 2016 at 10:32:33AM +0200, Ulrike Fischer wrote:
> Am Mon, 16 May 2016 20:07:49 -0400 schrieb Scott Kostyshak:
>
> > If we use the new syntax of
> >
> > \pageheight\paperheight
> > \pagewidth\paperwidth
>
> Why don't you do as David suggest and load the luatex85 package?

Because the package is quite new and many LyX users do not have it. One
possibility is to use the package if it is available and not use it if
it is not (without changing any of the other code exported by LyX). Do
you think this would lead to good results for users? Specifically, do
you think a significant amount of users (imagine a diverse mix of
Mac/Win/Linux) would have LaTeX installations with "new luatex" but
without the luatex85 package available? My guess is that it is not that
common. Let's add on the further condition that a user of LyX actually
*uses* LuaTeX.

In the long-run, it would be nice for LyX to eventually export correct
LuaTeX code and not rely on a transition package.

> luatex85 can also be loaded if you compile with pdflatex and
> xelatex, it will then quit silently and so you can use
> \pdfpageheight\paperheight in all formats (\pageheight would give an
> error with pdflatex and xelatex).
>
>
> > Using the dvilualatex command
>
> Why are you doing this?

I don't and I don't even know why anyone would want to. But LyX supports
exporting to DVI via dvilualatex and as long as we support that I will
try my best to make sure it works properly. We have made a lot of tests
for code that LyX exports. When one of those tests goes from passing to
failing, I try to investigate whether it is a regression in an
underlying package or if (as in this case) we need to change something
in LyX's export. The challenge when we change something is often
ensuring that the exported code still works for old LaTeX installations.