[tex-live] A bug after upgrading expl3

[Benoit RIVET]

After upgrading expl3 (and all the rest of my texlive installation), compiling the following innocent code :

% !TEX TS-program = luaLaTeX
\documentclass{article}
\usepackage{unicode-math, lipsum}
\begin{document}
\lipsum
\end{document}

stops after the following log :

(some lines suppressed)
(/usr/local/texlive/2010/texmf-dist/tex/latex/expl3/l3luatex.sty

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! 
! This is a LaTeX bug: check coding!
! 
! Command `\lua_shipout_x:n' not yet defined!
! 
! See the LaTeX3 documentation for further information.
! For immediate help type H <return>.
!...............................................  
                                                  
l.68 \cs_generate_variant:Nn \lua_shipout_x:n
                                              { x }

There is no such problem when I don't use unicode-math, and the file compiles fine when reverting to the backup version of expl3.