! LaTeX Error: Inconsistent local/global assignment

[muzimuzhi]

% !TeX program = xelatex
\documentclass{fduthesis}

\ExplSyntaxOn
\debug_on:n { check-declarations }
\ExplSyntaxOff

\fdusetup{
  style/footnote-style = pifont*
}

\begin{document}
\end{document}

一大串 ! LaTeX Error: Inconsistent local/global assignment 的第一个是

! LaTeX Error: Inconsistent local/global assignment

For immediate help type H <return>.
 ...                                              

l.10 }

This is a coding error.

Global assignment to a local variable '\l__fdu_fn_style_tl'.

从 https://github.com/nju-lug/NJUThesis/issues/240#issuecomment-1990592673 吸引来的。