Do not specify an SDK version in object files

This is unnecessary, since it ends up being overwritten when linking
anyhow, and it feels wrong to embed some arbitrary SDK version in here.

1 files changed, 7 insertions, 3 deletions

diff --git a/compiler/rustc_codegen_ssa/src/back/metadata.rs b/compiler/rustc_codegen_ssa/src/back/metadata.rs
index 06433484ea3..8857fda1e97 100644
--- a/compiler/rustc_codegen_ssa/src/back/metadata.rs
+++ b/compiler/rustc_codegen_ssa/src/back/metadata.rs
@@ -402,13 +402,17 @@ fn macho_object_build_version_for_target(target: &Target) -> object::write::Mach
     let platform =
         rustc_target::spec::current_apple_platform(target).expect("unknown Apple target OS");
     let min_os = rustc_target::spec::current_apple_deployment_target(target);
-    let (sdk_major, sdk_minor) =
-        rustc_target::spec::current_apple_sdk_version(platform).expect("unknown Apple target OS");
 
     let mut build_version = object::write::MachOBuildVersion::default();
     build_version.platform = platform;
     build_version.minos = pack_version(min_os);
-    build_version.sdk = pack_version((sdk_major, sdk_minor, 0));
+    // The version here does not _really_ matter, since it is only used at runtime, and we specify
+    // it when linking the final binary, so we will omit the version. This is also what LLVM does,
+    // and the tooling also allows this (and shows the SDK version as `n/a`). Finally, it is the
+    // semantically correct choice, as the SDK has not influenced the binary generated by rustc at
+    // this point in time.
+    build_version.sdk = 0;
+
     build_version
 }