lilypond-book latex input duplicating

[Jason Addison]

If I \input{something} twice in a lytex file, it gets duplicated by
lilypond-book. How do I keep this from happening?

I'm using lilypond 2.22.2, from brew.

For example:

inp.lytex:
>>>>
\documentclass[]{book}
\begin{document}
Hey!
\input{you}
Hey!
\input{you}
\end{document}
<<<<

you.tex:
>>>>
You!
<<<<

command:
$ lilypond-book --output=out --pdf inp.lytex

now see out/you.tex:
$ cat out/you.tex
You!
You!

There are 2 "You!" strings, and the pdf file, from running "pdflatex
inp.tex" in out/, looks like:

Hey! You! You! Hey! You! You!

What I expect is:

Hey! You! Hey! You!

By the way, if I input it three times it gets triplicated. If I do it
once, it is normal.

Thanks,
Jason