No rust-std support for s390x-unknown-linux-musl

[uweigand]

My understanding is that the rust compiler and library sources should now contain everything needed to support Rust on the s390x-unknown-linux-musl target. In fact, the s390x Alpine distro now comes with a Rust package.

However, I still get:

$ rustup target add s390x-unknown-linux-musl
error: toolchain 'stable-x86_64-unknown-linux-gnu' does not contain component 'rust-std' for target 's390x-unknown-linux-musl'
note: not all platforms have the standard library pre-compiled: https://doc.rust-lang.org/nightly/rustc/platform-support.html

What would need to be done to enable this target?

[Urgau]

https://doc.rust-lang.org/nightly/rustc/platform-support.html say that std isn't officially supported for s390x-unknown-linux-musl. It also state that the target is a Tier-3 target, that means that no build artifacts are generate, even if std would have been supported.

As to why alpine was able to build for it, I would say luck or the docs isn't up to date.

There is however a way to build std with a nighlty compiler by using Cargo -Zbuild-std experimental feature.