Rustup does not recognize Alpine Linux

Hello, I am trying to compile Rust on Alpine Linux in iSh, on iPad. Unfortunately, when I run

curl --proto='https' -tlsv1.2 -sSf https://sh.rustup.rs | sh

I get the following error message:

rustup: command failed: downloader https://static.rust-lang.org/rustup/dist/i686-unknown-linux-musl/rustup-init /tmp/tmp.OHeHe/rustup-init

The i686-unknown-linux-musl target is a tier 2 target, which means that for example tests are not being run. In this case it also means that rustc, cargo and rustup are not available. For the 64bit linux musl target, they are available though.