Provide full Apple Silicon (arm64/AArch64-Apple-Darwin) support in rustup

[monkeydom]

Describe the problem you are trying to solve

Provide full compatibility for Apple Silicon (AArch64/Arm64) based macs. DTKs are out there now, user facing machines will be soonish.

Describe the solution you'd like

Let AArch64-Apple-Darwin just be a fully supported platform for rustup

Notes

Note that apple currently reports arm64 as architecture.

current output:

rust % curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
rustup: unknown CPU type: arm64 

[monkeydom]

when adding a arm64 to the aarch64 switch case, the next error one gets is:

rustup: command failed: downloader https://static.rust-lang.org/rustup/dist/aarch64-apple-darwin/rustup-init /var/folders/sq/89_rr1cd3h7g3643mmd1lg280000gn/T/tmp.fP8JB2EA/rustup-init aarch64-apple-darwin

[monkeydom]

Main Compiler support seems to be tracked at
rust-lang/rust#73908

[shepmaster]

There's no real work to be done here — Rustup compiles fine on the DTK. Once there are official Rust builds, rustup tarballs will be able to be created and uploaded. The most I see so far is updating the shell script as appropriate.

% file $(which rustup)
/Users/shep/.cargo/bin/rustup: Mach-O 64-bit executable arm64

% rustup --version
rustup 1.21.1+259 (138d33e50 2020-07-01)

Unfortunately, the tests don't yet run:

---- update_no_manifest stdout ----
thread 'update_no_manifest' panicked at 'not implemented', tests/mock/clitools.rs:1131:13

test result: FAILED. 0 passed; 23 failed; 0 ignored; 0 measured; 0 filtered out

[kinnison]

The shell script is still real work. However, if there's no Rust coding to do then the real work boils down to the shell script changes needed and the CI work needed.

[shepmaster]

Yes, I neglected to mention the CI work, mostly because that's something that is broadly unknown — we don't even know how we are going to do it for Rust itself yet. There's likely to be some way to cross-compile from x86_64 to aarch64 (which is what I've done by hand so far), but not actually execute the tests.

My hope is that the shell script changes will be a one or two line change (maybe just rewriting arm64 to aarch64, for example).

[kinnison]

I am hoping we will implement something to ensure that the target is properly supported as a triple, as part of build.rs at some point, so yes, hopefully there'll just be some shell tweaks and then the CI. If the Github Actions provided MacOS runners can cross to the target then we'll be sorted once the toolchain dockers are ready (assuming those run on macos too?)

[shepmaster]

Status:

• Build for aarch64-apple-darwin #2521
• Treat Apple's arm64 as aarch64 #2525

The current assumption is that things will "just work" in the next rustup release.

[AhmedSoliman]

When is the next release date to get support for Apple M1?

[kinnison]

There's a few more issues we need to resolve before the next release, but I'm hoping within a couple of weeks for the rustup release.

[shepmaster]

For people who don't mind getting their hands dirty, you can download the x86_64 version of rustup and then build the current development branch natively.

• Install x86_64 rustup and aarch64 rustc / cargo:

  arch --x86_64 \
  sh <(curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs) \
  --default-host aarch64-apple-darwin \
  --default-toolchain nightly
  

• Clone this repo

• Build it and install as usual

Of course, this will be whatever arbitrary commit you check out, but I think it's fine 😇

[MaxDesiatov]

* Install x86_64 `rustup` and aarch64 `rustc` / `cargo`:
  ```
  arch --x86_64 \
  sh <(curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs) \
  --default-host aarch64-apple-darwin \
  --default-toolchain nightly
  ```

* Clone this repo

* [Build it and install as usual](https://github.com/rust-lang/rustup/blob/master/CONTRIBUTING.md)

I found that with these instructions most crates fail to build. I saw that building with RUSTC=$(rustup which rustc) $(rustup which cargo) install <your_crate> should fix that until native rustup is released, but I haven't tried that yet.