rustup does not check if rosetta installed on mac

[babinskiy]

Verification

• I searched for recent similar issues at https://github.com/rust-lang/rustup/issues?q=is%3Aissue+is%3Aopen%2Cclosed and found no duplicates.
• I am on the latest version of Rustup according to https://github.com/rust-lang/rustup/tags and am still able to reproduce my issue.

Problem

Since version 1.28.0, rustup checks if the host system is compatible and fails the installation if it is not (see #4028). However, Apple M1 systems are compatible with x86_64 architecture if Rosetta is installed. Unfortunately, rustup does not account for this compatibility.

Steps

0. Have an Apple M1 box with Rosetta

%  sysctl -a | grep machdep.cpu.brand
machdep.cpu.brand_string: Apple M1

1. Try to install x64 rust toolchain:

% rustup toolchain install 1.85.0-x86_64-apple-darwin
error: toolchain '1.85.0-x86_64-apple-darwin' may not be able to run on this system
note: to build software for that platform, try `rustup target add x86_64-apple-darwin` instead
note: add the `--force-non-host` flag to install the toolchain anyway

Possible Solution(s)

Use --force-non-host flag:

% rustup toolchain install --force-non-host 1.85.0-x86_64-apple-darwin
info: syncing channel updates for '1.85.0-x86_64-apple-darwin'

  1.85.0-x86_64-apple-darwin unchanged - rustc 1.85.0 (4d91de4e4 2025-02-17)

Notes

No response

Rustup version

rustup 1.28.1 (f9edccde0 2025-03-05)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `rustc 1.85.0 (4d91de4e4 2025-02-17)`

Installed toolchains

Default host: aarch64-apple-darwin
rustup home:  /Users/administrator/.rustup

installed toolchains
--------------------
stable-aarch64-apple-darwin
beta-aarch64-apple-darwin
nightly-aarch64-apple-darwin
1.65.0-aarch64-apple-darwin
1.65.0-x86_64-apple-darwin
1.71.0-aarch64-apple-darwin
1.71.0-x86_64-apple-darwin
1.74.0-aarch64-apple-darwin
1.74.0-x86_64-apple-darwin
1.75.0-aarch64-apple-darwin
1.75.0-x86_64-apple-darwin
1.78.0-aarch64-apple-darwin
1.78.0-x86_64-apple-darwin
1.80.0-aarch64-apple-darwin
1.80.0-x86_64-apple-darwin
1.80.1-aarch64-apple-darwin
1.80.1-x86_64-apple-darwin
1.85.0-aarch64-apple-darwin (active, default)
1.85.0-x86_64-apple-darwin

active toolchain
----------------
name: 1.85.0-aarch64-apple-darwin
active because: it's the default toolchain
installed targets:
  aarch64-apple-darwin

OS version

ProductName:    macOS
ProductVersion: 11.7.10
BuildVersion:   20G1427

[djc]

Why do you want to insist on installing a non-native version? And why is the --force-non-host option not good enough for your use case?

[rami3l]

@djc Back in v1.26.0 rustup would happily accept x64 as a native host and we have got a lot for surprising behaviors because of that (mostly linkage errors). That's why we accepted juliaup's patch explicitly for detecting Rosetta 2 and are now warning the user about it. As such I don't think we'll be working in the opposite direction...

[djc]

@rami3l yes, that is also my stance -- I was pushing back.