missing chapter numbering

[poshenchang]

Minimal reproduction:

#import "@preview/mousse-notes:1.1.0": *

#set page(paper: "us-letter")
#show: book.with(
  title: [Title],
  subtitle: [Subtitle],
  font-style: "serif",
)

#outline(indent: auto)
#pagebreak()

Compiling on Typst 0.14.2 produces:

error: expected string or function, found none