LilyPond v2.20.0 on Raspberry Pi OS (Debian buster)

[renyhp]

Hello everyone,

I have installed LilyPond v2.18.2 on my Raspberry Pi 4 from the
repositories, and I now would like to upgrade the current stable
version.

The arm architecture of the Raspberry Pi does not make it possible to
use the installer on the website.

The repositories for Raspbian and Debian do include arm builds, but the
buster repositories are still on v2.18.2.

I found some old thread on the very same topic here, but the only arm
deb package I could find is the one for v2.21.0.

I am now wondering whether the deb file I'm searching for exists on the
internet. If it doesn't, does that mean I will have to compile it
myself? I'm not sure I will be able to do that. Also, if I manage to,
I am willing to contribute to the community by sharing the build, but
again, I don't really know how.

Thank you all in advance for your help!
  renyhp