[texhax] Mysterious error message

[Michael Barr]

I am facing a mysterious error that I really cannot fathom.  It would be
too complicated to reproduce it, but I know from experience that some
errors are so characteristic that experienced users will recognize the
mostly useless error report immediately (e.g. spacefactor errors).  The
change (in where \@address appears) from

\AtEndDocument{%
\newpage\thispagestyle{empty}%
 % \@address
 %  \@filelocation
\@endstuff}

\def\@endstuff{\newpage\thispagestyle{empty}
\@address
\@filelocation
 ...other stuff that doesn't concern us}

which compiles (under pdflatex) without error, to

\AtEndDocument{%
\newpage\thispagestyle{empty}%
\@address
 %  \@filelocation
\@endstuff}

\def\@endstuff{\newpage\thispagestyle{empty}
 % \@address
\@filelocation

elicits this error:

! Use of \@icentercr doesn't match its definition.
<argument> \def

l.56 \end{document}

? x

Moving \@filelocation has the same effect.  To simplify, I defined
\def\@address{xxx}.  One other thing is that the previous line
of the original file was

\includepdf[pages={1,3}]{ahsorig.pdf}

The error disappears if you change that line to

\includepdf[pages={1-3}]{ahsorig.pdf}

That presumably means that the error is still there, but does not appear
from some reason.  In fact, that is the main reason I want to track it
down since I can obviously work around it.  But I have always found it
worth the effort to track down all errors.

Michael Barr