test helpers: do not use default build system

Sources/_InternalTestSupport/SwiftTesting+TraitConditional.swift

@@ -11,6 +11,7 @@
 
 import class Foundation.FileManager
 import class Foundation.ProcessInfo
+import class PackageModel.UserToolchain
 import Basics
 import Testing
 
@@ -29,6 +30,13 @@ extension Trait where Self == Testing.ConditionTrait {
         }
     }
 
+    /// Enabled only if toolchain support swift concurrency
+    public static var requiresSwiftConcurrencySupport: Self {
+        enabled("skipping because test environment doesn't support concurrency") {
+            (try? UserToolchain.default)!.supportsSwiftConcurrency()
+        }
+    }
+
     /// Skip test unconditionally
     public static func skip(_ comment: Comment? = nil) -> Self {
         disabled(comment ?? "Unconditional skip, a comment should be added for the reason") { true }

Sources/_InternalTestSupport/XCTAssertHelpers.swift

@@ -154,7 +154,7 @@ public func XCTAssertBuilds(
     env: Environment? = nil,
     file: StaticString = #file,
     line: UInt = #line,
-    buildSystem: BuildSystemProvider.Kind = .native
+    buildSystem: BuildSystemProvider.Kind,
 ) async {
     for conf in configurations {
         await XCTAssertAsyncNoThrow(
@@ -184,7 +184,7 @@ public func XCTAssertSwiftTest(
     env: Environment? = nil,
     file: StaticString = #file,
     line: UInt = #line,
-    buildSystem: BuildSystemProvider.Kind = .native
+    buildSystem: BuildSystemProvider.Kind,
 ) async {
     await XCTAssertAsyncNoThrow(
         try await executeSwiftTest(
@@ -211,7 +211,7 @@ public func XCTAssertBuildFails(
     env: Environment? = nil,
     file: StaticString = #file,
     line: UInt = #line,
-    buildSystem: BuildSystemProvider.Kind = .native
+    buildSystem: BuildSystemProvider.Kind,
 ) async -> CommandExecutionError? {
     var failure: CommandExecutionError? = nil
     await XCTAssertThrowsCommandExecutionError(
@@ -337,6 +337,6 @@ public func XCTExhibitsGitHubIssue(_ number: Int) throws {
 
     try XCTSkipIf(
         ProcessInfo.processInfo.environment[envVar] != nil,
-        "https://github.com/swiftlang/swift-package-manager/issues/\(number): \(envVar)environment variable is set"
+        "https://github.com/swiftlang/swift-package-manager/issues/\(number): \(envVar) environment variable is set"
     )
 }

Sources/_InternalTestSupport/misc.swift

@@ -395,7 +395,7 @@ public func executeSwiftBuild(
     Xld: [String] = [],
     Xswiftc: [String] = [],
     env: Environment? = nil,
-    buildSystem: BuildSystemProvider.Kind = .native,
+    buildSystem: BuildSystemProvider.Kind,
     throwIfCommandFails: Bool = true,
 ) async throws -> (stdout: String, stderr: String) {
     let args = swiftArgs(
@@ -419,7 +419,7 @@ public func executeSwiftRun(
     Xld: [String] = [],
     Xswiftc: [String] = [],
     env: Environment? = nil,
-    buildSystem: BuildSystemProvider.Kind
+    buildSystem: BuildSystemProvider.Kind,
 ) async throws -> (stdout: String, stderr: String) {
     var args = swiftArgs(
         configuration: configuration,
@@ -444,7 +444,7 @@ public func executeSwiftPackage(
     Xld: [String] = [],
     Xswiftc: [String] = [],
     env: Environment? = nil,
-    buildSystem: BuildSystemProvider.Kind = .native
+    buildSystem: BuildSystemProvider.Kind,
 ) async throws -> (stdout: String, stderr: String) {
     let args = swiftArgs(
         configuration: configuration,
@@ -466,7 +466,7 @@ public func executeSwiftPackageRegistry(
     Xld: [String] = [],
     Xswiftc: [String] = [],
     env: Environment? = nil,
-    buildSystem: BuildSystemProvider.Kind = .native
+    buildSystem: BuildSystemProvider.Kind,
 ) async throws -> (stdout: String, stderr: String) {
     let args = swiftArgs(
         configuration: configuration,
@@ -489,7 +489,7 @@ public func executeSwiftTest(
     Xswiftc: [String] = [],
     env: Environment? = nil,
     throwIfCommandFails: Bool = false,
-    buildSystem: BuildSystemProvider.Kind = .native
+    buildSystem: BuildSystemProvider.Kind,
 ) async throws -> (stdout: String, stderr: String) {
     let args = swiftArgs(
         configuration: configuration,

Tests/BuildTests/BuildSystemDelegateTests.swift

@@ -24,7 +24,7 @@ final class BuildSystemDelegateTests: XCTestCase {
             // These linker diagnostics are only produced on macOS.
             try XCTSkipIf(true, "test is only supported on macOS")
             #endif
-            let (fullLog, _) = try await executeSwiftBuild(fixturePath)
+            let (fullLog, _) = try await executeSwiftBuild(fixturePath, buildSystem: .native)
             XCTAssertTrue(fullLog.contains("ld: warning: search path 'foobar' not found"), "log didn't contain expected linker diagnostics")
         }
     }
@@ -40,11 +40,11 @@ final class BuildSystemDelegateTests: XCTestCase {
         let executableExt = ""
         #endif
         try await fixtureXCTest(name: "Miscellaneous/TestableExe") { fixturePath in
-            _ = try await executeSwiftBuild(fixturePath)
+            _ = try await executeSwiftBuild(fixturePath, buildSystem: .native)
             let execPath = fixturePath.appending(components: ".build", "debug", "TestableExe1\(executableExt)")
             XCTAssertTrue(localFileSystem.exists(execPath), "executable not found at '\(execPath)'")
             try localFileSystem.removeFileTree(execPath)
-            let (fullLog, _) = try await executeSwiftBuild(fixturePath)
+            let (fullLog, _) = try await executeSwiftBuild(fixturePath, buildSystem: .native)
             XCTAssertFalse(fullLog.contains("replacing existing signature"), "log contained non-fatal codesigning messages")
         }
     }

Tests/BuildTests/IncrementalBuildTests.swift

@@ -42,7 +42,7 @@ final class IncrementalBuildTests: XCTestCase {
         try XCTSkipIf(!UserToolchain.default.supportsSDKDependentTests(), "skipping because test environment doesn't support this test")
         try await fixtureXCTest(name: "CFamilyTargets/CLibrarySources") { fixturePath in
             // Build it once and capture the log (this will be a full build).
-            let (fullLog, _) = try await executeSwiftBuild(fixturePath)
+            let (fullLog, _) = try await executeSwiftBuild(fixturePath, buildSystem: .native)
 
             // Check various things that we expect to see in the full build log.
             // FIXME:  This is specific to the format of the log output, which
@@ -64,15 +64,15 @@ final class IncrementalBuildTests: XCTestCase {
             let llbuildContents1: String = try localFileSystem.readFileContents(llbuildManifest)
 
             // Now build again.  This should be an incremental build.
-            let (log2, _) = try await executeSwiftBuild(fixturePath)
+            let (log2, _) = try await executeSwiftBuild(fixturePath, buildSystem: .native)
             XCTAssertMatch(log2, .contains("Compiling CLibrarySources Foo.c"))
 
             // Read the second llbuild manifest.
             let llbuildContents2: String = try localFileSystem.readFileContents(llbuildManifest)
 
             // Now build again without changing anything.  This should be a null
             // build.
-            let (log3, _) = try await executeSwiftBuild(fixturePath)
+            let (log3, _) = try await executeSwiftBuild(fixturePath, buildSystem: .native)
             XCTAssertNoMatch(log3, .contains("Compiling CLibrarySources Foo.c"))
 
             // Read the third llbuild manifest.
@@ -91,7 +91,7 @@ final class IncrementalBuildTests: XCTestCase {
             )
 
             // Now build again.  This should be an incremental build.
-            let (log4, _) = try await executeSwiftBuild(fixturePath)
+            let (log4, _) = try await executeSwiftBuild(fixturePath, buildSystem: .native)
             XCTAssertMatch(log4, .contains("Compiling CLibrarySources Foo.c"))
         }
     }
@@ -101,7 +101,7 @@ final class IncrementalBuildTests: XCTestCase {
         try await fixtureXCTest(name: "ValidLayouts/SingleModule/Library") { fixturePath in
             @discardableResult
             func build() async throws -> String {
-                return try await executeSwiftBuild(fixturePath).stdout
+                return try await executeSwiftBuild(fixturePath, buildSystem: .native).stdout
             }
 
             // Perform a full build.
@@ -135,7 +135,11 @@ final class IncrementalBuildTests: XCTestCase {
         try await fixtureXCTest(name: "ValidLayouts/SingleModule/Library") { fixturePath in
             @discardableResult
             func build() async throws -> String {
-                return try await executeSwiftBuild(fixturePath, extraArgs: ["--disable-build-manifest-caching"]).stdout
+                return try await executeSwiftBuild(
+                    fixturePath,
+                    extraArgs: ["--disable-build-manifest-caching"],
+                    buildSystem: .native,
+                ).stdout
             }
 
             // Perform a full build.
@@ -166,7 +170,11 @@ final class IncrementalBuildTests: XCTestCase {
 
             let newSdkPathStr = "/tmp/../\(sdkPathStr)"
             // Perform a full build again because SDK changed.
-            let log1 = try await executeSwiftBuild(fixturePath, env: ["SDKROOT": newSdkPathStr]).stdout
+            let log1 = try await executeSwiftBuild(
+                fixturePath,
+                env: ["SDKROOT": newSdkPathStr],
+                buildSystem: .native,
+            ).stdout
             XCTAssertMatch(log1, .contains("Compiling Library"))
         }
 #endif

Tests/BuildTests/PluginsBuildPlanTests.swift

@@ -21,7 +21,7 @@ final class PluginsBuildPlanTests: XCTestCase {
         try XCTSkipOnWindows(because: "Fails to build the project to due to incorrect Path handling.  Possibly related to https://github.com/swiftlang/swift-package-manager/issues/8511")
 
         try await fixtureXCTest(name: "Miscellaneous/Plugins/MySourceGenPlugin") { fixturePath in
-            let (stdout, _) = try await executeSwiftBuild(fixturePath)
+            let (stdout, _) = try await executeSwiftBuild(fixturePath, buildSystem: .native)
             XCTAssertMatch(stdout, .contains("Build complete!"))
             // FIXME: This is temporary until build of plugin tools is extracted into its own command.
             XCTAssertTrue(localFileSystem.exists(fixturePath.appending(RelativePath(".build/plugin-tools.db"))))
@@ -49,7 +49,11 @@ final class PluginsBuildPlanTests: XCTestCase {
 
         // By default, plugin dependencies are built for the host platform
         try await fixtureXCTest(name: "Miscellaneous/Plugins/CommandPluginTestStub") { fixturePath in
-            let (stdout, stderr) = try await executeSwiftPackage(fixturePath, extraArgs: ["-v", "build-plugin-dependency"])
+            let (stdout, stderr) = try await executeSwiftPackage(
+                fixturePath,
+                extraArgs: ["-v", "build-plugin-dependency"],
+                buildSystem: .native,
+            )
             XCTAssertMatch(stdout, .contains("Hello from dependencies-stub"))
             XCTAssertMatch(stderr, .contains("Build of product 'plugintool' complete!"))
             XCTAssertTrue(
@@ -66,7 +70,11 @@ final class PluginsBuildPlanTests: XCTestCase {
 
         // When cross compiling the final product, plugin dependencies should still be built for the host
         try await fixtureXCTest(name: "Miscellaneous/Plugins/CommandPluginTestStub") { fixturePath in
-            let (stdout, stderr) = try await executeSwiftPackage(fixturePath, extraArgs: ["--triple", targetTriple, "-v", "build-plugin-dependency"])
+            let (stdout, stderr) = try await executeSwiftPackage(
+                fixturePath,
+                extraArgs: ["--triple", targetTriple, "-v", "build-plugin-dependency"],
+                buildSystem: .native,
+            )
             XCTAssertMatch(stdout, .contains("Hello from dependencies-stub"))
             XCTAssertMatch(stderr, .contains("Build of product 'plugintool' complete!"))
             XCTAssertTrue(