General ⇒ size-limit for aux, problem w/ hyperref, natbib, include

[kawski]

Is there a size limit to .aux files? My trouble started with a 150 page
set of class-notes when I "\include"d the last section. Eventually,
I found that by removing at least 10 labels I got the whole file to
compile correctly. Over some 10 hours I stripped almost everything
until just the following remain, the driver a.tex (below) and the
included file c.tex (on bottom). I managed to get the file to compile
or not by just forcing the addition of one character to one of the
entries of the .aux file. I read about issues between hyperref and
cite, but this also happens with natbib. The \include command appears
to be essential for this error to happen. (I never got the error
with \input.) I am really confused by what mechanism the addition
of a single character to one entry in the .aux file can cause an error.

The type of entries (labels, theorems, section etc.) does not appear
to matter. Very confusing was when stripping the original 20,000 lines
an error apparently happened because repagination changed one .aux
file entry from page 9 to page 10 i.e. {9} --> {10}, one extra character
led to miscompilation. Both "latex a" and "pdflatex a" give this error.
---------------------------------------------------
%%% typical error message
[2] (./a.aux (./c.aux)
Runaway argument?
{{53}{2}{subsection title 1\relax }{equation.53
! File ended while scanning use of \@newl@bel.
<inserted text>
\par
l.14 \@input{c.aux}
---------------------------------------------------
%%% the driver: a.tex
\documentclass{article}
\usepackage[hypertex]{hyperref}
%\usepackage{cite}
\usepackage{natbib}
\newcommand{\be}{\begin{equation}}
\newcommand{\ee}{\end{equation}}
\begin{document}
\include{c}
\end{document}
---------------------------------------------------
%%% the included file: c.tex
\section{section title A}

\subsection{subsection title 1}

\be \label{labelname01} a \ee
\be \label{labelname02} b \ee
\be \label{labelname03} c \ee
\be \label{labelname04} d \ee
\be \label{labelname05} e \ee
\be \label{labelname06} f \ee
\be \label{labelname07} g \ee
\be \label{labelname08} h \ee
\be \label{labelname09} i \ee
\be \label{labelname10} j \ee
\be \label{labelname11} a \ee
\be \label{labelname12} b \ee
\be \label{labelname13} c \ee
\be \label{labelname14} d \ee
\be \label{labelname15} e \ee
\be \label{labelname16} f \ee
\be \label{labelname17} g \ee
\be \label{labelname18} h \ee
\be \label{labelname19} i \ee
\be \label{labelname20} j \ee
\be \label{labelname21} a \ee
\be \label{labelname22} b \ee
\be \label{labelname23} c \ee
\be \label{labelname24} d \ee
\be \label{labelname25} e \ee
\be \label{labelname26} f \ee
\be \label{labelname27} g \ee
\be \label{labelname28} h \ee
\be \label{labelname29} i \ee
\be \label{labelname30} j \ee
\be \label{labelname31} a \ee
\be \label{labelname32} b \ee
\be \label{labelname33} c \ee
\be \label{labelname34} d \ee
\be \label{labelname35} e \ee
\be \label{labelname36} f \ee
\be \label{labelname37} g \ee
\be \label{labelname38} h \ee
\be \label{labelname39} i \ee
\be \label{labelname40} j \ee
\be \label{labelname51} a \ee
\be \label{labelname52} b \ee
\be \label{labelname53} c \ee
\be \label{labelname54} d \ee
\be \label{labelname55} e \ee
\be \label{labelname56} f \ee
\be \label{labelname57} g \ee
\be \label{labelname58} h \ee
\be \label{labelname59} i \ee
\be \label{labelname60} j \ee
\be \label{labelname61} a \ee
\be \label{labelname62} b \ee
\be \label{labelname63} c \ee
\end{document}

[phi]

In the example you posted, the error is caused simply by the spurious \end{document} at the end of c.tex.

[kawski]

thank you.

that solves the problem for now -- apparently \include is different
from \input (if there is a duplicate \end{document})

but I am still confused how adding one extra bibtex entry, even changing
the length of one entry by one character makes the difference between
compiling without problem, and complaining about a "runaway document".
What is the mechanism behind this error?

[josephwright]

You could be hitting the line length limit of BibTeX: this can sometimes be a problem. It's awkward to get right, sometimes.

[kawski]

that is what I thought at first -- I had long section titles, and hyperref
(or cite or natbib) repeated tjhem for every entry. But that is why I removed
line by line... from a 20,000 line document to identify the source of the
error until I came up with the sample I listed above... it has all short
lines. Yet I managed to have pdflatex compile correctly or send the error
by just making one label-name one character longer, any label name that
I tried. One of the weirdest disappearance of errors occurred when a
completely innocent paragraph was removed -- but this caused one .aux
entry to change from page {...}{10} to pager {...}{9}.

where would such character limit for .aux files be set?