MACOSX_DEPLOYMENT_TARGET ignored

[andreyrd]

Setting the MACOSX_DEPLOYMENT_TARGET when building a rust library will make sure that the library has a minimum supported OS of that version. rust-lang/cargo#4667

Ring seems to just default to the current system version in it's build script, meaning my compiled library now can't link against anything built for an older version.

(Same problem for iOS too, btw)

[francesca64]

Proposed solution: When building for macOS/iOS, ring's build.rs should read the MACOSX_DEPLOYMENT_TARGET/IPHONEOS_DEPLOYMENT_TARGET env vars, and default to the same minimums Rust specifies if they're not set. After that, the minimum version would be passed to clang using -mmacosx-version-min/-mios-version-min.

The current minimums chosen by Rust (and their potential future change) are listed here: rust-lang/rust#104385

I'll create a PR.

[francesca64]

It looks like this is actually an upstream issue: rust-lang/cc-rs#708

However, the existing code suggests that this should already work for iOS: https://github.com/rust-lang/cc-rs/blob/57853c4bf8a89a0f4c9137eb367ac580305c6919/src/lib.rs#L2294-L2328

@andreyrd can you confirm that you're experiencing this issue on iOS?

[francesca64]

@briansmith this is an upstream issue and can be closed.

I've successfully resolved it by using the linked fork, so this will be resolved for everyone once a new release of cc is cut.

(Even if @andreyrd is still having issues on iOS, that would still be be a cc issue.)

[briansmith]

@briansmith this is an upstream issue and can be closed.

Thanks for following up! Closing this as you suggest.