[SwiftBuild] Build output folder no longer includes the target triple

[marcprux]

With the "native" (soon to be legacy) build system, we could build for multiple target triples:

$ swiftly run swift build --show-bin-path -c debug --swift-sdk x86_64-unknown-linux-android28 +6.3.1
.build/x86_64-unknown-linux-android28/debug

$ swiftly run swift build --swift-sdk aarch64-unknown-linux-android28 +6.3.1
$ swiftly run swift build --swift-sdk armv7-unknown-linux-android28 +6.3.1
$ swiftly run swift build --swift-sdk x86_64-unknown-linux-android28 +6.3.1

and then grab the resulting shared objects from .build/aarch64-unknown-linux-android28/debug/, .build/armv7-unknown-linux-android28/debug/, and .build/x86_64-unknown-linux-android28/debug/ to bundle into our Android .apk for multi-architecture support.

But now with swift-build:

$ swiftly run swift build --build-system native --show-bin-path -c debug --swift-sdk x86_64-unknown-linux-android28 +swift-DEVELOPMENT-SNAPSHOT-2026-04-30-a
.build/x86_64-unknown-linux-android28/debug
warning: '--build-system native' has been deprecated and will be removed in a future release; please report an issue at https://github.com/swiftlang/swift-package-manager/issues if you are unable to adopt the default build system.

$ swiftly run swift build --show-bin-path -c debug --swift-sdk x86_64-unknown-linux-android28 +swift-DEVELOPMENT-SNAPSHOT-2026-04-30-a
.build/out/Products/Debug-android

$ swiftly run swift build --swift-sdk aarch64-unknown-linux-android28 +swift-DEVELOPMENT-SNAPSHOT-2026-04-30-a
$ swiftly run swift build --swift-sdk armv7-unknown-linux-android28 +swift-DEVELOPMENT-SNAPSHOT-2026-04-30-a
$ swiftly run swift build --swift-sdk x86_64-unknown-linux-android28 +swift-DEVELOPMENT-SNAPSHOT-2026-04-30-a

everything is dropped into .build/out/Products/Debug-android/, without the triple included in the output path, and clobbers the previous triple's build. Is this by design? Is there any possibility we might get the triple included in the output folder?

This might also affect other SDKs that build for multiple triples (e.g., x86_64-swift-linux-musl and aarch64-swift-linux-musl).

[marcprux]

CC @swiftlang/android-workgroup as this will break the Gradle build scripts in https://github.com/swiftlang/swift-android-examples (and likely many other build/packaging workflows, like swiftlang/github-workflows#269 and skiptools/swift-android-action#21)

[dschaefer2]

Moving to SwiftBuild.

[marcprux]

I'll also note that the change to the output folders is going to require updating various docs that reference specific build output folders for Swift SDKs, such as:

• https://www.swift.org/documentation/articles/static-linux-getting-started.html
• https://www.swift.org/documentation/articles/swift-sdk-for-android-getting-started.html
• https://docs.swift.org/android/documentation/android/gettingstarted

[owenv]

assigning to myself so it doesn't get lost but I likely won't get to this until next week