LaTeX-command \input crashes lilypond-book 2.22.1

[Andreas K . H . von Rüden]

Hello,

using lilypond 2.20.0 on Ubuntu 20.04, lilypond-book worked perfectly. After
Update to Ubuntu 21.10 and lilypond 2.22.1, lilypond-book crashes, when the
lytex-file contains the \input command.

Here's an MWE:

lytex-file:
---
\documentclass{scrartcl}
\begin{document}
\input{bugtest}
Test.
\lilypondfile{bugtest.ly}
\end{document}
---

lilypond-file (bugtest.ly):
---
\version "2.22.1"
\language "deutsch"

\score {
  \new Voice {
    \relative c' {
      c d e f
    }
  }
  \layout{}
}
---

tex-file to be included (bugtest.tex):
---
This should be included.
---

When the \input command in the lytex-file is changed do \include, it works,
but latex produces a different output, which is undesired.

---
Andreas