File ended while scanning use of \__iow_wrap_end_chunk:w

[jszhao]

After update to the latest l3kernel, I have encountered the error message:

File ended while scanning use of \__iow_wrap_end_chunk:w

Here are the two minimal examples

\documentclass{standalone}
\usepackage{xeCJK}
\setCJKfamilyfont{wb}{FZWeiBei-S03}
\begin{document}
English
\end{document}

The error message is:

Runaway argument?
76543210\q_stop newline - 'small caps'  (m/sc) with NFSS spec.: ^^I^^O\ETC.
! File ended while scanning use of \__iow_wrap_end_chunk:w.
<inserted text>

The another example:

\documentclass{standalone}
\usepackage{xeCJK}
\setCJKmonofont[ItalicFont=KaiTi]{FangSong}
\begin{document}
English
\end{document}

Runaway argument?
76543210\q_stop newline  ^^I^^O^^W^^_^^W^^R^^A^^Pnewline  This font f\ETC.
! File ended while scanning use of \__iow_wrap_end_chunk:w.
<inserted text>

Although they may be related with xeCJK package, I reported here since they occurred after updating l3kernel. And I searching google, the only page that contains \__iow_wrap_end_chunk:w points me to this project.

[davidcarlisle]

I think this is a #491 which is fixed in the sources, sorry for the inconvenience.

[josephwright]

Duplicate of #491.