% Test error unwinding

\documentclass{article}

\begin{document}
\errorcontextlines=20

\newtoks\testa
\testa={a \the\testb c}
\newtoks\testb
\testb={b \errmessage{Error message}}
\the\testa

\end{document}

%% status: 1

%% output:
%% T-unwind-error.tex:12: error: Error message
%%       at <inserted text> b \errmessage {Error message}
%%     from <inserted text> a \the \testb c
%%                                        ^
%%     from \the\testa
%% There were errors; output/x.pdf not updated
