Cross-compiling tests doesn't work if a package uses macros

[finagolfin]

Is it reproducible with SwiftPM command-line tools: swift build, swift test, swift package etc?

• Confirmed reproduction steps with SwiftPM CLI. The description text must include reproduction steps with either of command-line SwiftPM commands, swift build, swift test, swift package etc.

Description

It always fails with an error like this with my Android SDK bundles:

error: Failed opening '/home/finagolfin/swift-syntax/Examples/.build/aarch64-unknown-linux-android24/debug/index/store/v5/units/AddAsyncMacroTests.swift.o-20XPE2PQ2J7J7': No such file or directory

I first reported this bug in April, nothing has changed since.

Expected behavior

The tests to cross-compile

Actual behavior

Weird errors that it can't find a file

Steps to reproduce

1. ~/swift-6.0.2-RELEASE-fedora39/usr/bin/swift sdk install ~/swift-6.0.2-RELEASE-android-24-0.1.artifactbundle.tar.gz
2. cd swift-syntax/Examples
3. ~/swift-6.0.2-RELEASE-fedora39/usr/bin/swift build --build-tests --swift-sdk aarch64-unknown-linux-android24

It fails with a similar error for the latest trunk 6.1 SDK bundle used by the command ~/swift-DEVELOPMENT-SNAPSHOT-2024-10-30-a-ubi9/usr/bin/swift build --build-tests --swift-sdk aarch64-unknown-linux-android24 -Xswiftc -disallow-use-new-driver, with that last flag needed because of a swift-driver 6.1 regression, swiftlang/swift-driver#1723.

Swift Package Manager version/commit hash

SwiftPM 6.0 and 6.1, cross-compiling packages that use macros didn't work at all before that

Swift & OS version (output of swift --version ; uname -a)

Swift 6.0.2/6.1 cross-compiling the swift-syntax example or swift-foundation tests for Android AArch64 from linux x86_64

[finagolfin]

@marcprux, can you generate a linux SDK bundle on macOS using the swift-sdk-generator and see if this reproduces with the linux SDK bundle also?

[marcprux]

If I create a MacroDemo project with swift package init --type macro, it fails to cross-compile with a similar error:

$ ~/Library/Developer/Toolchains/swift-6.0.2-RELEASE.xctoolchain/usr/bin/swift build --swift-sdk 6.0.2-RELEASE_ubuntu_jammy_aarch64 --build-tests

Fetching https://github.com/apple/swift-syntax.git from cache
Fetched https://github.com/apple/swift-syntax.git from cache (0.02s)
Creating working copy for https://github.com/apple/swift-syntax.git
Working copy of https://github.com/apple/swift-syntax.git resolved at 510.0.3
Building for debugging...
…
clang: warning: argument unused during compilation: '-pie' [-Wunused-command-line-argument]
error: Failed opening '/opt/src/github/MacroDemo/.build/aarch64-swift-linux-musl/debug/index/store/v5/units/MacroDemoTests.swift.o-OV9PWKAUKWEY': No such file or directory

The same error occurs with the 6.0.2-RELEASE_ubuntu_jammy_aarch64 (which I built with swift-sdk-generator: swift run swift-sdk-generator make-linux-sdk --swift-version 6.0.2-RELEASE), as well as with both the Musl SDK (swift-6.0.2-RELEASE_static-linux-0.0.1) and the Android SDK (swift-6.0.2-RELEASE-android-24-0.1).

[marcprux]

Note that this might not affect all macros, but might be some specific issue with SwiftSyntaxMacros (or SwiftSyntaxMacrosTestSupport). If I create a variant of the sample macro project that just tests the #stringify macro directly (see MacroDemoLibTests.swift), then it builds successfully and the tests pass on Android.

[finagolfin]

Thanks for checking, Marc.