Am 26.06.2011 um 21:27 schrieb Pablo Rodríguez:

> Hi there,
> 
> I have just tried to compile the following sample:
> 
> \documentclass{article}
> \usepackage{fontspec}
> \setmainfont{Minion Pro}
> \usepackage[spanish]{babel}
> \usepackage{unicode-math}
> \setmathfont{Minion Pro}
> \begin{document}
> $\frac{27,7}{100\,000}$ en varones
> \end{document}
> 
> And it works with XeLaTeX, but not with LuaLaTeX. It seems to have
> problems with spanish from babel, but this is a must for me.
> 
> I'm using TL 2010 updated as right now.
> 
> I wonder whether this is a bug or I am missing something. Could anyone
> be so kind to tell me what is wrong here?

A short update on this: while we can fix this on the lualatex-math/unicode-math end (see the discussion at GitHub), it is only a symptom of a deeper problem, namely that the \mathcode, \mathchardef, \delcode, \radical etc. primitives are deprecated with LuaTeX since they (unlike \char etc.) can't easily be extended to allow Unicode code points. Therefore all packages that make use of any of these primitives need to be fixed. We already have several fixes in the lualatex-math package, but I think the best option would be to fix the package code directly. What do you think about this? Who would be responsible for things like the Babel problem?