As of Rust 1.74 (to be released on November 16th, 2023), the minimum version of Apple's platforms (iOS, macOS, and tvOS) that the Rust toolchain supports will be increased to newer minimums. These changes affect both the Rust compiler itself (rustc
), other host tooling, and most importantly, the standard library and any binaries produced that use it. With these changes in place, any binaries produced will stop loading on older versions or exhibit other, unspecified, behavior.
The new minimum versions are now:
If your application does not target or support macOS 10.7-10.11 or iOS 7-9 already these changes most likely do not affect you.
The following contains each affected target, and the comprehensive effects on it:
x86_64-apple-darwin
(Minimum OS raised)aarch64-apple-ios
(Minimum OS raised)aarch64-apple-ios-sim
(Minimum iOS and macOS version raised.)x86_64-apple-ios
(Minimum iOS and macOS version raised. This is also a simulator target.)aarch64-apple-tvos
(Minimum OS raised)armv7-apple-ios
(Target removed. The oldest iOS 10-compatible device uses ARMv7s.)armv7s-apple-ios
(Minimum OS raised)i386-apple-ios
(Minimum OS raised)i686-apple-darwin
(Minimum OS raised)x86_64-apple-tvos
(Minimum tvOS and macOS version raised. This is also a simulator target.)From these changes, only one target has been removed entirely: armv7-apple-ios
. It was a tier 3 target.
Note that Mac Catalyst and M1/M2 (aarch64
) Mac targets are not affected, as their minimum OS version already has a higher baseline. Refer to the Platform Support Guide for more information.
These changes remove support for multiple older mobile devices (iDevices) and many more Mac systems. Thanks to @madsmtm
for compiling the list.
As of this update, the following device models are no longer supported by the latest Rust toolchain:
A total of 27 Mac system models, released between 2007 and 2009, are no longer supported.
The affected systems are not comprehensively listed here, but external resources exist which contain lists of the exact models. They can be found from Apple and Yama-Mac, for example.
The third generation AppleTV (released 2012-2013) is no longer supported.
Prior to now, Rust claimed support for very old Apple OS versions, but many never even received passive testing or support. This is a rough place to be for a toolchain, as it hinders opportunities for improvement in exchange for a support level many people, or everyone, will never utilize. For Apple's mobile platforms, many of the old versions are now even unable to receive new software due to App Store publishing restrictions.
Additionally, the past two years have clearly indicated that Apple, which has tight control over toolchains for these targets, is making it difficult-to-impossible to support them anymore. As of XCode 14, last year's toolchain release, building for many old OS versions became unsupported. XCode 15 continues this trend. After enough time, continuing to use an older toolchain can even lead to breaking build issues for others.
We want Rust to be a first-class option for developing software for and on Apple's platforms, but to continue this goal we have to set an easier, and more realistic compatibility baseline. The new requirements were determined after surveying what Apple and third-party statistics are available to us and picking a middle ground that balances compatibility with Rusts's needs and limitations.
If you or an application you develop are affected by this change, there are different options which may be helpful:
If your project does not directly support a specific version, but instead depends on a default previously used by Rust, there are some steps you can take to help improve. For example, a number of crates in the ecosystem have hardcoded Rust's default support versions since they haven't changed for a long time:
cc
crate to include build languages into your project, a future update will handle this transparently.rustc --print deployment-target
option for a default, or user-set, value on toolchains using Rust 1.71 or newer going forward. Hardcoded defaults should only be used for older toolchains where this is unavailable.