[OS X TeX] Problem with unicode-math and amsmath after migration towards Mountain Lion

[Franck Pastor]

Hello,

I've just migrated from Snow Leopard towards Mountain Lion (both with MacTeX 2012), and now most of  my LuaLaTeX files will not work. More precisely those who call simultaneously amsmath and unicode-math. An example:

% !TEX encoding = UTF-8 Unicode
% !TEX TS-program = LuaLaTeX
\documentclass{article}
%\usepackage{amsmath}
\usepackage{unicode-math}
\setmathfont{latinmodern-math}% latin modern math font installed recently
\begin{document}
	Try.
\end{document}

This file produces the following message of the console (nothing of that sort appears in the log file):

./try.tex:7: Undefined control sequence.
\__lltxmath_set_mathchar:NN ...def #1\lua_now_x:n 
                                                  {lualatex.math.print_class...
l.7 \begin{document}
                    
? h
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

It looks like a problem with LuaLaTeX itself, but I don't have a clue about what it is, and why it happens after my migration to Mountain Lion. Any idea?

Thanks in advance,

Franck Pastor