I have adopted the package, updated it to the latest version & fixed compilation issues. Apologies if things go wrong, this is my very first AUR package

If you are using sandbox (Like paru), rustup should use the latest cargo by default. If you are using the system's rustup, you need to update the rust toolchain manually. @geedorah

Was receiving this error:

Compiling hashbrown v0.12.0
error: edition 2021 is unstable and only available with -Z unstable-options.

error: could not compile `hashbrown`

To learn more, run the command again with --verbose.
warning: build failed, waiting for other jobs to finish...
error: build failed
==> ERROR: A failure occurred in build().
    Aborting...
 -> error making: beancount-language-server

It seems the rustup package has a /slightly/ outdated cargo that does not support "edition 2021". After removing rustup and instead installing rust and cargo this package builds properly.