Tracking issue for RFC 2837: "Demote Apple 32bit targets to Tier 3"

[pietroalbini]

This is a tracking issue for the RFC "Demote Apple 32bit targets to Tier 3" (rust-lang/rfcs#2837).

• Rust 1.41.0 (2020-01-30) will be the last release with the current support tier
• Rust 1.42.0 (2020-03-12) will have Tier 3 support for all Apple 32bit targets

Steps:

• Create a post on the main blog explaining the change to our users
  • PR: [main blog] Reducing support for 32-bit Apple targets blog.rust-lang.org#487
• Update docs.rs to stop building documentation for that target
  • PR: Drop support for building 32-bit Apple docs docs.rs#541
• Remove the targets from the CI builders
  • PR: ci: remove 32-bit Apple targets #67732

Steps after Rust 1.42 is released:

• Update platform support and the component history to reflect the demotion

[pietroalbini]

I will write the implementation PRs shortly.

Edit: done!

[fpotter]

From rust-lang/rfcs#2837 (comment) (not sure where discussion belongs)

---

I'm late, but... Apple does continue to support 32-bit for iOS devices and the simulator.

Using Catalina and Xcode 11.3 with a deployment target set to iOS 10.0 or earlier, I can build an app for i386 and armv7.

If I download the iOS 10 simulator and set the simulated device to "iPhone 5", I can run that i386 binary in the simulator on Catalina.

iOS 11 was the first release to go 64-bit only, but plenty of apps continue to support iOS 10.0 or below which may run on both 32-bit and 64-bit devices.

[pietroalbini]

@fpotter hmm, that wouldn't help with the i686-apple-darwin target right?

Anyway, I don't feel Apple will keep 32-bit iOS support forever, and reducing support for everything related to 32-bit Apple in one sweep is probably better.