如果使用该选项加载,chemmacros
则会引发编译错误。! LaTeX error: "kernel/non-declared-variable"!!
expl3
[check-declarations]
\documentclass{article}
% RN. 8 August 2018
%=======================
\usepackage[check-declarations]{expl3}
\usepackage{chemmacros}
%-----------------------
\begin{document}
Hi there!
\end{document}