AucTeX 11.90 (Emacs 25.2) gives the following error instead of a warning when using Tikz Externalize:
! Package tikz Warning: The key 'up to date check=md5' is impossible, there is no macro to compute MD5. Falling back to 'up to date check=diff'.
Though my PDF compiles fine, I find the false error quite annoying. Any help in resolving this will be appreciated.
I have the following custom set variables in my init file:
'(TeX-debug-bad-boxes t)
'(TeX-debug-warnings t)
'(TeX-display-help nil)
'(TeX-engine (quote xetex))
'(TeX-error-overview-open-after-TeX-run t)
'(TeX-source-correlate-mode t)
'(TeX-source-correlate-start-server t)
MWE:
\documentclass[12pt]{article}
\usepackage{fontspec,realscripts}
\defaultfontfeatures{Ligatures=TeX,Scale=MatchLowercase}
\setmainfont[Scale=1]{Libertinus Serif}
\usepackage{tikz}
\usetikzlibrary{external} \tikzexternalize[prefix=tikz/]
\begin{document}
\begin{figure}
\centering
\begin{tikzpicture}
\draw (0,0) -- (1,0) -- (1,1) -- (0,1) -- (0,0);
\end{tikzpicture}
\end{figure}
\end{document}
%%% Local Variables:
%%% TeX-command-extra-options: "-shell-escape"
%%% End:
!
as errors rather than warnings. I think there was a good reason for this... For the record, also TeXstudio takes that warning as an error. – giordano May 29 '17 at 10:56