not possible to specify ios/macos versions requirements when cross-compiling for ios

[mtak-]

I want some way to pass these arguments through cargo while doing a cross compile to iOS:

• miphoneos-version-min
• mios-simulator-version-min
• mmacos-version-min

I don't see a way to do accomplish this without breaking either the build.rs scripts or the actual cross-compiled code.

Setting the environment variable MACOSX_DEPLOYMENT_TARGET will set mmacos-version-min for the build.rs scripts (yay) and the cross compiled code (boo - fails to build). The story is the reverse with IPHONEOS_DEPLOYMENT_TARGET - breaks build scripts, and works for the cross-compiled code.

Certain libraries like metal-rs have min iOS version requirements greater than iOS 7.0 which appears to be the default, so it'd be pretty handy if there was a way to tweak these flags.

I'm thinking there might be a way using RUSTC_WRAPPER or some sort of .cargo/config, but I haven't fully investigated it yet.

#29664 seems a little related.

[ForceBru]

So, is there a way to pass these arguments yet? I tried setting IPHONEOS_DEPLOYMENT_TARGET="12.0", but still got the following while building rustc:

CXXFLAGS_aarch64-apple-ios = Some("-fPIC --target=aarch64-apple-ios -arch arm64 -miphoneos-version-min=7.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.1.sdk -fembed-bitcode")

When I set CFLAGS="-miphoneos-version-min=12.0", this variable changes:

CXXFLAGS_aarch64-apple-ios = Some("-fPIC -miphoneos-version-min=12.0 --target=aarch64-apple-ios -arch arm64 -miphoneos-version-min=7.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.1.sdk -fembed-bitcode")

But there's still the option -miphoneos-version-min=7.0, which comes after the one that's set to 12.0, so the latter is overridden...

[ovasquez]

Any updates about this issue? I'm using the env variable IPHONEOS_DEPLOYMENT_TARGET and it's not using it to specify the minimum version.

[seungillee]

I'm also curious about this issue. Is there any way to specify minimum ios deployment target version?

[keith]

theoretically IPHONEOS_DEPLOYMENT_TARGET should control this, any idea where the version is coming from? I believe this is where it's supposed to be handled

rust/compiler/rustc_target/src/spec/apple_base.rs

Lines 292 to 295 in 271dcc1

	fn ios_deployment_target() -> (u32, u32) {
	// If you are looking for the default deployment target, prefer `rustc --print deployment-target`.
	from_set_deployment_target("IPHONEOS_DEPLOYMENT_TARGET").unwrap_or((10, 0))
	}

and with a quick test I see it working:

% cargo build --target aarch64-apple-ios-sim
% otool -lv target/aarch64-apple-ios-sim/debug/lolrust | grep -A2 IOSS
 platform IOSSIMULATOR
    minos 17.0
      sdk 17.0
% IPHONEOS_DEPLOYMENT_TARGET=14.0 cargo build --target aarch64-apple-ios-sim
% otool -lv target/aarch64-apple-ios-sim/debug/lolrust | grep -A2 IOSS
 platform IOSSIMULATOR
    minos 14.0
      sdk 17.0

[madsmtm]

Triage: I believe the original issue was about setting both MACOSX_DEPLOYMENT_TARGET and IPHONEOS_DEPLOYMENT_TARGET, this was fixed in #64254, so this issue can be closed.

Concretely, the following now works for running build scripts locally with a deployment target of macOS 11, and building the binary with a deployment target of iOS 14:

MACOSX_DEPLOYMENT_TARGET=11.0 IPHONEOS_DEPLOYMENT_TARGET=14.0 cargo build --target aarch64-apple-ios-sim