Acro and package option short-format: “Missing control sequence inserted”

This example fails to compile with Missing control sequence inserted.

\documentclass{article}
\usepackage[short-format={\scshape}]{acro}
%\acsetup{short-format={\scshape}}
\DeclareAcronym{acc}{short=a, long=A}
\begin{document}
\ac{acc}
\end{document}


Putting the package option inside of \acsetup instead solves the problem.

Is this a (known?) bug? Is it expected? (I don’t think I’ve seen anything about this in the manual, but I could have missed it, or perhaps my version of Acro (2.7) is outdated.)

• package options are expanded when processed (for all packages), so yes it is expected that fragile commands breaks. – Ulrike Fischer Dec 21 '18 at 17:29
• @UlrikeFischer Thanks, that’s the answer I looked for. Perhaps this question should then be closed as a duplicate, or your comment become an answer? – Olivier Cailloux Dec 24 '18 at 8:02