hey folks!

Have you got this nasty error message?

This is pdfTeX, Version 3.1415926-2.5-1.40.14 (TeX Live 2013/Arch Linux) restricted \write18 enabled.---! /var/lib/texmf/web2c/pdftex/latex.fmt doesn't match pdftex.pool(Fatal format file error; I'm stymied)

Then you should do the following:

… copying the *.pacnew files in /etc/texmf over the non .pacnew files and running fmtutil –all fixes the issue.

Found here: https://bbs.archlinux.org/viewtopic.php?id=166163