Fix ORT linking for macOS cross-builds.

.gitea/workflows/release.yml

@@ -47,8 +47,8 @@ jobs:
     runs-on: linux-arm64
     container: ghcr.io/rust-cross/cargo-zigbuild@sha256:82af75c41958c2af2787e8bedd912da7678a9438937e223e9d83d006d747b38b
     env:
-      CARGO_TARGET_AARCH64_APPLE_DARWIN_RUSTFLAGS: -C link-arg=-mmacosx-version-min=26.0 -C link-arg=-Wl,-rpath,@executable_path/../Resources -C link-arg=-Wl,-headerpad,0x1000
-      CARGO_TARGET_X86_64_APPLE_DARWIN_RUSTFLAGS: -C link-arg=-mmacosx-version-min=26.0 -C link-arg=-Wl,-rpath,@executable_path/../Resources -C link-arg=-Wl,-headerpad,0x1000
+      CARGO_TARGET_AARCH64_APPLE_DARWIN_RUSTFLAGS: -Lnative=target/macos-linker -C link-arg=-mmacosx-version-min=26.0 -C link-arg=-Wl,-rpath,@executable_path/../Resources -C link-arg=-Wl,-headerpad,0x1000
+      CARGO_TARGET_X86_64_APPLE_DARWIN_RUSTFLAGS: -Lnative=target/macos-linker -C link-arg=-mmacosx-version-min=26.0 -C link-arg=-Wl,-rpath,@executable_path/../Resources -C link-arg=-Wl,-headerpad,0x1000
     steps:
       - name: Check out the tag
         env:
@@ -78,6 +78,8 @@ jobs:
           RELEASE_ID: ${{ needs.prepare-release.outputs.release_id }}
         run: |
           set -eu
+          cargo +${RUST_TOOLCHAIN} run --locked --package bds-release -- \
+            macos-linker-alias target/macos-linker
           for build in \
             'aarch64-apple-darwin|aarch64-apple-darwin|darwin-arm64' \
             'x86_64-apple-darwin|x86_64-apple-darwin|darwin-x64'

crates/bds-release/src/main.rs

@@ -8,6 +8,9 @@ fn main() -> Result<(), Box<dyn Error>> {
     match args.as_slice() {
         [command] if command == "prepare" => gitea::prepare(),
         [command] if command == "publish" => gitea::publish(),
+        [command, directory] if command == "macos-linker-alias" => {
+            packaging::prepare_macos_linker_alias(Path::new(directory))
+        }
         [command, paths @ ..] if command == "upload" && !paths.is_empty() => {
             gitea::upload(paths.iter().map(Path::new))
         }
@@ -36,7 +39,7 @@ fn main() -> Result<(), Box<dyn Error>> {
             gitea::upload(assets.iter().map(|path| path.as_path()))
         }
         _ => Err(
-            "usage: bds-release prepare|publish|upload <asset>...|package <tag> <release-dir> <rust-lib-dir> <platform> <dist-dir> [--upload]"
+            "usage: bds-release prepare|publish|macos-linker-alias <directory>|upload <asset>...|package <tag> <release-dir> <rust-lib-dir> <platform> <dist-dir> [--upload]"
                 .into(),
         ),
     }

crates/bds-release/src/packaging.rs

@@ -24,6 +24,12 @@ const LC_REEXPORT_DYLIB: u32 = 0x8000_001f;
 const LC_LAZY_LOAD_DYLIB: u32 = 0x20;
 const LC_LOAD_UPWARD_DYLIB: u32 = 0x8000_0023;
 
+pub(crate) fn prepare_macos_linker_alias(directory: &Path) -> Result<(), Box<dyn Error>> {
+    fs::create_dir_all(directory)?;
+    fs::write(directory.join("libclang_rt.osx.a"), b"!<arch>\n")?;
+    Ok(())
+}
+
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 enum Platform {
     MacOs,
@@ -460,6 +466,17 @@ mod tests {
         assert_eq!(dmg_sectors(1).unwrap(), 131_072);
     }
 
+    #[test]
+    fn macos_cross_linker_alias_is_an_empty_static_archive() {
+        let temp = tempdir().unwrap();
+        prepare_macos_linker_alias(temp.path()).unwrap();
+
+        assert_eq!(
+            fs::read(temp.path().join("libclang_rt.osx.a")).unwrap(),
+            b"!<arch>\n"
+        );
+    }
+
     #[test]
     fn windows_package_contains_the_app_without_dynamic_std() {
         let temp = tempdir().unwrap();

crates/bds-ui/tests/packaging_assets.rs

@@ -119,6 +119,8 @@ fn tagged_releases_are_built_and_packaged_with_rust_tools() {
         "tags:",
         "runs-on: linux-arm64",
         "cargo-zigbuild",
+        "macos-linker-alias",
+        "-Lnative=target/macos-linker",
         "aarch64-apple-darwin",
         "x86_64-apple-darwin",
         "aarch64-unknown-linux-gnu",