footnote with babel `bidi=default` raises an error in LuaLaTeX

[fabon-f]

\RequirePackage{latexbug}
\documentclass{article}
\usepackage[bidi=default]{babel}
\begin{document}
\footnote{AAA}
\end{document}

This code raises an error when using LuaLaTeX:

warning  (hpack filter): error: [\directlua]:1: attempt to index a nil value (f
ield 'characters')

.
\mbox  #1->\leavevmode \hbox {#1}

l.5 \footnote{
            AAA}
?

I found that commit 0bf72d4a12 causes this error.

[jbezos]

This is, indeed, the problematic commit. I’ll fix it in GitHub in a few days.