beamer and utf8x inputenc leads to Runaway argument error

[ebuchlin]

Hello,

Beamer and inputenc with utf8x encoding have recently become incompatible, with this file:

\documentclass{beamer}
\usepackage[utf8x]{inputenc}

\begin{document}
\end{document}

producing errors starting by:

! Argument of � has an extra }.
<inserted text> 
                \par 
l.4 \begin{document}

Runaway argument?
! Paragraph ended before � was complete.
<to be read again> 
                   \par 
l.4 \begin{document}

! Argument of � has an extra }.
<inserted text> 
                \par 
l.4 \begin{document}

Runaway argument?
! Paragraph ended before � was complete.
<to be read again> 
                   \par 
l.4 \begin{document}

! Argument of � has an extra }.
<inserted text> 
                \par 
l.4 \begin{document}
(...)

A similar code worked last month. It still works with utf8 instead of utf8x. It still works with utf8x but with another class such as article (so it is not a utf8x inputenc-specific issue).

About my system:

• Up-to-date Ubuntu 22.10 PC
• LaTeX installation from Ubuntu packages:
  • pdflatex (pdfTeX 3.141592653-2.6-1.40.24) and inputenc.sty (2021/02/14 v1.3d) from texlive-latex-base 2022.20220722-1
  • beamer.cls (2022/05/17 v3.67) from texlive-latex-recommended 2022.20220722-1
  • utf8x.def (2004/10/17) from texlive-latex-extra 2022.20220722-2

[josephwright]

There are significant technical issues with the utf8x code, and it is not recommended for use at all. I do not plan to make any changes in beamer to try to keep it working.

[ebuchlin]

OK, I will use utf8 instead... Still an additional information for readers of this issue: although the packages seem not to have changed from last summer (at least), I have recently updated from Ubuntu 22.04 to 22.10.

[josephwright]

@ebuchlin It's not your Ubunut version that's important, it's the LaTeX kernel release that you have; that will likely have been updated

[josephwright]

BTW, your example compiles fine with the latest TeX Live installation (TL'22 or TL'23-pretest)