test: fix macOS concurrent validation harness

.github/workflows/ci.yml

@@ -49,16 +49,49 @@ jobs:
   macos-swift-6:
     name: Swift 6 / macOS 15
     runs-on: macos-15
+    env:
+      DEVELOPER_DIR: /Applications/Xcode_16.4.app/Contents/Developer
     steps:
       - name: Check out repository
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
-      - name: Require Swift 6
-        run: swift --version | grep -E "Swift version 6\\."
+      - name: Report and require pinned toolchain
+        run: |
+          swift --version
+          xcodebuild -version
+          uname -a
+          sw_vers
+          test "$(uname -m)" = "arm64"
+          swift --version | grep -F "Apple Swift version 6.1.2"
+          xcodebuild -version | grep -F "Xcode 16.4"
       - name: Validate package manifest
         run: swift package describe
       - name: Build
         run: swift build
       - name: Test
         run: swift test
+      - name: Collect test crash diagnostics
+        if: failure()
+        run: |
+          destination="$RUNNER_TEMP/securetoolkit-test-diagnostics"
+          mkdir -p "$destination"
+          {
+            swift --version
+            xcodebuild -version
+            uname -a
+            sw_vers
+          } > "$destination/environment.txt"
+          if [ -d "$HOME/Library/Logs/DiagnosticReports" ]; then
+            find "$HOME/Library/Logs/DiagnosticReports" -maxdepth 1 -type f \
+              \( -name 'SecureToolKit*' -o -name 'swift-test*' \) \
+              -exec cp '{}' "$destination" \;
+          fi
+          find .build -type d -name '*.xcresult' -exec cp -R '{}' "$destination" \;
+      - name: Upload test crash diagnostics
+        if: failure()
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02
+        with:
+          name: macos-test-diagnostics
+          path: ${{ runner.temp }}/securetoolkit-test-diagnostics
+          if-no-files-found: error
       - name: Lint formatting
         run: swift format lint --recursive --strict Package.swift Sources Tests

Tests/SecureToolKitTesting/ConfirmationValidationTests.swift

@@ -1,6 +1,13 @@
 import SecureToolKitCore
 import XCTest
 
+private enum ConcurrentConfirmationValidationOutcome: Sendable, Equatable {
+    case matched
+    case mismatched
+    case rejected(Phase7Failure)
+    case unexpectedFailure
+}
+
 final class ConfirmationValidationTests: XCTestCase {
     func `testP7POS008ExactArtifactAndIndependentContextProduceEligibility`() throws {
         let fixture = try Phase7ValidationFixture()
@@ -177,21 +184,35 @@ final class ConfirmationValidationTests: XCTestCase {
     func `testConcurrentValidationIsPureAndDeterministic`() async throws {
         let fixture = try Phase7ValidationFixture()
         let expected = try fixture.eligibility()
-        let values = try await withThrowingTaskGroup(
-            of: ConfirmedIssuanceEligibility.self,
-            returning: [ConfirmedIssuanceEligibility].self
+        let challenge = fixture.artifactFixture.authorityFixture.challenge
+        let artifact = fixture.artifact
+        let context = fixture.context
+        let outcomes = await withTaskGroup(
+            of: ConcurrentConfirmationValidationOutcome.self,
+            returning: [ConcurrentConfirmationValidationOutcome].self
         ) { group in
             for _ in 0..<100 {
-                group.addTask { try fixture.eligibility() }
+                group.addTask {
+                    do {
+                        return try fixture.eligibility() == expected ? .matched : .mismatched
+                    } catch let failure as Phase7Failure {
+                        return .rejected(failure)
+                    } catch {
+                        return .unexpectedFailure
+                    }
+                }
             }
-            var results: [ConfirmedIssuanceEligibility] = []
-            for try await value in group {
-                results.append(value)
+            var results: [ConcurrentConfirmationValidationOutcome] = []
+            for await outcome in group {
+                results.append(outcome)
             }
             return results
         }
-        XCTAssertEqual(values.count, 100)
-        XCTAssertTrue(values.allSatisfy { $0 == expected })
+        XCTAssertEqual(outcomes.count, 100)
+        XCTAssertTrue(outcomes.allSatisfy { $0 == .matched })
+        XCTAssertEqual(challenge, fixture.artifactFixture.authorityFixture.challenge)
+        XCTAssertEqual(artifact, fixture.artifact)
+        XCTAssertEqual(context, fixture.context)
     }
 
     func `testValidationDoesNotMutateInputsOrReserveReplayState`() throws {