Build for ARM Musl targets

[lilianmoraru]

Rust now supports these additional targets:

arm-unknown-linux-musleabi
arm-unknown-linux-musleabihf
armv7-unknown-linux-musleabihf

Could we get builds for these targets?

[lilianmoraru]

ping @alexcrichton @brson

[alexcrichton]

cc @japaric as well

Unfortunately it's pretty difficult to add these today. Even if we had an image with all the relevant libc.a files in it we'd have to have a way of pointing the build system at all of them simultaneously. The ./configure script only supports at most one musl target, and while rustbuild supports more than one at a time it isn't easily configurable from buildbot.

Will basically take some refactoring to get this to work.

[alexcrichton]

Targets are added and deployed!

[alexcrichton]

Nightlies should hopefully come tomorrow night, but I'll debug failures if they happen.

[lilianmoraru]

Thank you!

[alexcrichton]

Complications last night prevented these nightlies from going out, hopefully tonight though!

[lilianmoraru]

@alexcrichton rustup still says 'arm-unknown-linux-musleabi' is unavailable for download
Where could I check the status for these?

I see this one passed: https://buildbot.rust-lang.org/builders/nightly-dist-rustc-cross-rustbuild-linux/builds/7
It has musl in there. Maybe I use the rustup command wrongly(rustup target add arm-unknown-linux-musleabi)?

[japaric]

I see this one passed

All the "nightly-dist-*" jobs here must pass (become green) but looks like one of the last steps, nightly-dist-packaging-linux, failed today.

[alexcrichton]

Another hiccup last night, but a new nightly and these targets are now out.

[lilianmoraru]

Yey, it works now.
Thanks!!