Add support for aarch64-unknown-linux-musl (alpine armv8)

[gidjituser]

Cannot install rust on an arm based alpine linux distribution. In my case armv8 (64-bit). musl is only supported on x86.

It would be great to support the platform aarch64-unknown-linux-musl

[kinnison]

This looks like it ought to be possible, based on the platform support list. I guess someone needs to work out the right docker bits. Should be an easy contribution if you want to give it a go. I'm willing to help if someone shows up on our Discord too.

[gidjituser]

Thanks. I am pretty new to rust, however I will try and give it a stab.

I am currently using latest docker edge for the platform capability.

FROM balenalib/aarch64-alpine
# Install build tools
RUN apk add --no-cache build-base gcc pkgconfig curl file git openssl-dev 
ENV PATH=/root/.cargo/bin:$PATH
# Install Rust
RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y 

docker buildx build --platform linux/arm64 -t my/rust-image .

rustup-init.sh fails in get_bitness() as head -c 5 /proc/self/exe errors with Bad descriptor. Might need an alternative to getting bitness (32 or 64 bit) without dependencies.

[mati865]

There is no possibility to do it right now because aarch64-unknown-linux-musl is target only (does not provide cargo and rustc) because Rust does not have enough CI budget.

[kinnison]

So it is :( I shall remove the easy/mentor tags for now, thanks @mati865

[gidjituser]

Thanks for the updates. Currently rust arm64 docker images are quite large. Cannot use alpine or build static as that requires musl. Hopefully this will get in the pipeline at some point.

[alex]

Is this the sort of thing that would be enabled by the ongoing work to add aarch64 CI for Rust, and making it a T1 platform? (rust-lang/rfcs#2959)

[rbtcollins]

Probably; I can't imagine that rustup wouldn't be able to install a Tier 1 triple.