# How can I use \appendix with Beamer's ignorenonframetext option?

I am almost certain that the following used to work just fine. However, it certainly doesn't work any more.

I have workshop materials (based on UK TUG's) which use wrappers to input a common file containing the material for slides, handouts and notes. ignorenonframetext is used to avoid having the workshop exercises appear in the slides.

Last year, I started supplementing the handouts by adding appendices. This worked great. This also worked in November. It does not, alas, work now.

MNWE:

\documentclass[ignorenonframetext]{beamer}

\begin{document}
\begin{frame}{some frame}
some frame
\end{frame}

\appendix

\section{appendix}
some stuff
\end{document}


I first get lots and lots of messages saying

Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding):
(hyperref)                removing \translate ' on input line 20.


This message is repeated numerous times, with exactly the same line number.

This is followed by numberous instances of the following message,

Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding):
(hyperref)                removing \translate ' on input line 21.


with, again, the same line number.

After a while removing \translate on lines 20 and 21, TeX gives up.

! TeX capacity exceeded, sorry [input stack size=5000].
<inserted text>
\<>-\translate
l.21

!  ==> Fatal error occurred, no output PDF file produced!


What has changed and what should be changing to avoid this problem?

I am compiling with pdfTeX. I get the same error with TeX, LuaTeX or XeTeX, however.