I updated my MiKTeX to the newest version a few days ago, and after this when I compile documents with the fontspec package included, there's a warning. For example:
\documentclass{article}
\usepackage{fontspec}
\setmainfont{Adobe Garamond Pro}
\begin{document}
Hello, world!
\end{document}
Build Output shows:
*************************************************
* LaTeX warning: "xparse/redefine-command"
*
* Redefining document command \oldstylenums with arg. spec. 'm' on line 107.
*************************************************
Why this happens? How to solve it?
xparseraise a warning whenever one use\RenewDocumentCommand, since redefining a macro is always at some risk. There are also some other innocuous warnings, e.g. some of the font substitution warnings. – Leo Liu Mar 4 '12 at 1:58info, not a warning. – Andrey Vihrov Mar 4 '12 at 7:31