# Weird unasked-for file trace in LaTeX

Doug McKenna doug at mathemaesthetics.com
Mon Dec 9 02:18:16 CET 2019

I can't tell if this is a bug or by design, but ...

Execute this MWE for the LaTeX format (TeX Live 2017):

\tracingcommands=3
\tracingmacros=1
\tracingonline=1

\documentclass{article}
\begin{document}
Hello, world!
\end{document}

This sends a whole lot of tracing to the terminal, in which the following lines appear towards the end of it all, when producing the final single page:

\@arabic #1->\number #1
#1<-\c at page
{\number}
{the character 1}
{\hfil}
{end-group character }}
{internal vertical mode: \relax}
{end-group character }}
{end-group character }}
[1{/usr/local/texlive/2017/texmf-var/fonts/map/pdftex/updmap/pdftex.map}]
{\endgroup}

Some sort of a complete file read occurs smack dab in the middle of printing out "[1]".  But notice that \tracingfiles has not been set.

Is this a bug?  Shouldn't that parenthesized file path not be output unless \tracingfiles has been set to 1?

Doug McKenna
Mathemaesthetics, Inc.