diff --git a/Sources/SWBTaskConstruction/TaskProducers/TaskProducer.swift b/Sources/SWBTaskConstruction/TaskProducers/TaskProducer.swift
index d5397dac..cd3c36d0 100644
--- a/Sources/SWBTaskConstruction/TaskProducers/TaskProducer.swift
+++ b/Sources/SWBTaskConstruction/TaskProducers/TaskProducer.swift
@@ -867,7 +867,7 @@ public class TaskProducerContext: StaleFileRemovalContext, BuildFileResolution
     }
 
     /// Report a note from task construction.
-    func note(_ message: String, location: Diagnostic.Location = .unknown, component: Component = .default) {
+    public func note(_ message: String, location: Diagnostic.Location = .unknown, component: Component = .default) {
         if let configuredTarget {
             delegate.note(.overrideTarget(configuredTarget), message, location: location, component: component)
         } else {
@@ -876,7 +876,7 @@ public class TaskProducerContext: StaleFileRemovalContext, BuildFileResolution
     }
 
     /// Report a warning from task construction.
-    func warning(_ message: String, location: Diagnostic.Location = .unknown, component: Component = .default) {
+    public func warning(_ message: String, location: Diagnostic.Location = .unknown, component: Component = .default) {
         if let configuredTarget {
             delegate.warning(.overrideTarget(configuredTarget), message, location: location, component: component)
         } else {
@@ -894,7 +894,7 @@ public class TaskProducerContext: StaleFileRemovalContext, BuildFileResolution
     }
 
     /// Report a remark from task construction.
-    func remark(_ message: String, location: Diagnostic.Location = .unknown, component: Component = .default) {
+    public func remark(_ message: String, location: Diagnostic.Location = .unknown, component: Component = .default) {
         if let configuredTarget {
             delegate.remark(.overrideTarget(configuredTarget), message, location: location, component: component)
         } else {
diff --git a/Sources/SWBUniversalPlatform/TestEntryPointTaskProducer.swift b/Sources/SWBUniversalPlatform/TestEntryPointTaskProducer.swift
index 23ec56f0..4730192c 100644
--- a/Sources/SWBUniversalPlatform/TestEntryPointTaskProducer.swift
+++ b/Sources/SWBUniversalPlatform/TestEntryPointTaskProducer.swift
@@ -36,12 +36,17 @@ class TestEntryPointTaskProducer: PhasedTaskProducer, TaskProducer {
                     guard settings.productType?.conformsTo(identifier: "com.apple.product-type.bundle.unit-test") == true else {
                         continue
                     }
+                    guard settings.globalScope.evaluate(BuiltinMacros.SWIFT_ENABLE_TESTABILITY) || settings.globalScope.evaluate(BuiltinMacros.OTHER_SWIFT_FLAGS).contains("-enable-testing") else {
+                        context.warning("Skipping XCTest discovery for '\(directDependency.target.name)' because it was not built for testing")
+                        continue
+                    }
                     guard settings.globalScope.evaluate(BuiltinMacros.SWIFT_INDEX_STORE_ENABLE) else {
-                        context.error("Cannot perform test discovery for '\(directDependency.target.name)' because index while building is disabled")
+                        context.warning("Skipping XCTest discovery for '\(directDependency.target.name)' because indexing was disabled")
                         continue
                     }
                     let path = settings.globalScope.evaluate(BuiltinMacros.SWIFT_INDEX_STORE_PATH)
                     guard !path.isEmpty else {
+                        context.warning("Skipping XCTest discovery for '\(directDependency.target.name)' because the index store path could not be determined")
                         continue
                     }
                     indexStoreDirectories.append(path)
diff --git a/Tests/SWBBuildSystemTests/BuildOperationTests.swift b/Tests/SWBBuildSystemTests/BuildOperationTests.swift
index 820558d1..80628efa 100644
--- a/Tests/SWBBuildSystemTests/BuildOperationTests.swift
+++ b/Tests/SWBBuildSystemTests/BuildOperationTests.swift
@@ -576,6 +576,133 @@ fileprivate struct BuildOperationTests: CoreBasedTests {
         }
     }
 
+    @Test(.requireSDKs(.host), .skipHostOS(.macOS), .skipHostOS(.windows, "cannot find testing library"))
+    func unitTestWithGeneratedEntryPoint_testabilityDisabled() async throws {
+        try await withTemporaryDirectory(removeTreeOnDeinit: false) { (tmpDir: Path) in
+            let testProject = try await TestProject(
+                "TestProject",
+                sourceRoot: tmpDir,
+                groupTree: TestGroup(
+                    "SomeFiles",
+                    children: [
+                        TestFile("library.swift"),
+                        TestFile("test.swift"),
+                    ]),
+                buildConfigurations: [
+                    TestBuildConfiguration("Debug", buildSettings: [
+                        "ARCHS": "$(ARCHS_STANDARD)",
+                        "CODE_SIGNING_ALLOWED": "NO",
+                        "PRODUCT_NAME": "$(TARGET_NAME)",
+                        "SDKROOT": "$(HOST_PLATFORM)",
+                        "SUPPORTED_PLATFORMS": "$(HOST_PLATFORM)",
+                        "SWIFT_VERSION": swiftVersion,
+                        "INDEX_DATA_STORE_DIR": "\(tmpDir.join("index").str)",
+                        "LINKER_DRIVER": "swiftc",
+                        "ENABLE_TESTABILITY": "NO",
+                        "SWIFT_ENABLE_TESTABILITY": "NO",
+                    ])
+                ],
+                targets: [
+                    TestStandardTarget(
+                        "UnitTestRunner",
+                        type: .swiftpmTestRunner,
+                        buildConfigurations: [
+                            TestBuildConfiguration("Debug", buildSettings: [
+                                "LD_RUNPATH_SEARCH_PATHS": "$(RPATH_ORIGIN)",
+                            ]),
+                        ],
+                        buildPhases: [
+                            TestSourcesBuildPhase(),
+                            TestFrameworksBuildPhase([
+                                "MyTests.so"
+                            ])
+                        ],
+                        dependencies: ["MyTests"]
+                    ),
+                    TestStandardTarget(
+                        "MyTests",
+                        type: .unitTest,
+                        buildConfigurations: [
+                            TestBuildConfiguration("Debug", buildSettings: [
+                                "LD_RUNPATH_SEARCH_PATHS": "$(RPATH_ORIGIN)",
+                                "LD_DYLIB_INSTALL_NAME": "MyTests.so"
+                            ])
+                        ],
+                        buildPhases: [
+                            TestSourcesBuildPhase(["test.swift"]),
+                            TestFrameworksBuildPhase([
+                                TestBuildFile(.target("library")),
+                            ])
+                        ], dependencies: [
+                            "library"
+                        ],
+                        productReferenceName: "MyTests.so"
+                    ),
+                    TestStandardTarget(
+                        "library",
+                        type: .dynamicLibrary,
+                        buildConfigurations: [
+                            TestBuildConfiguration("Debug", buildSettings: [
+                                "LD_RUNPATH_SEARCH_PATHS": "$(RPATH_ORIGIN)",
+                                "LD_DYLIB_INSTALL_NAME": "liblibrary.so",
+
+                                // FIXME: Find a way to make these default
+                                "EXECUTABLE_PREFIX": "lib",
+                                "EXECUTABLE_PREFIX[sdk=windows*]": "",
+                            ])
+                        ],
+                        buildPhases: [
+                            TestSourcesBuildPhase(["library.swift"]),
+                        ],
+                    )
+                ])
+            let core = try await getCore()
+            let tester = try await BuildOperationTester(core, testProject, simulated: false)
+            try localFS.createDirectory(tmpDir.join("index"))
+            let projectDir = tester.workspace.projects[0].sourceRoot
+
+            try await tester.fs.writeFileContents(projectDir.join("library.swift")) { stream in
+                stream <<< "public func foo() -> Int { 42 }\n"
+            }
+
+            try await tester.fs.writeFileContents(projectDir.join("test.swift")) { stream in
+                stream <<< """
+                    import Testing
+                    import XCTest
+                    import library
+                    @Suite struct MySuite {
+                        @Test func myTest() {
+                            #expect(foo() == 42)
+                        }
+                    }
+
+                    final class MYXCTests: XCTestCase {
+                        func testFoo() {
+                            XCTAssertTrue(true)
+                        }
+                    }
+                """
+            }
+
+            let destination: RunDestinationInfo = .host
+            try await tester.checkBuild(runDestination: destination, persistent: true) { results in
+                results.checkWarning(.prefix("Skipping XCTest discovery for 'MyTests' because it was not built for testing"))
+                results.checkNoErrors()
+
+                let environment = destination.hostRuntimeEnvironment(core)
+
+                do {
+                    let executionResult = try await Process.getOutput(url: URL(fileURLWithPath: projectDir.join("build").join("Debug\(destination.builtProductsDirSuffix)").join(core.hostOperatingSystem.imageFormat.executableName(basename: "UnitTestRunner")).str), arguments: [], environment: environment)
+                    #expect(String(decoding: executionResult.stdout, as: UTF8.self).contains("Executed 0 tests"))
+                }
+                do {
+                    let executionResult = try await Process.getOutput(url: URL(fileURLWithPath: projectDir.join("build").join("Debug\(destination.builtProductsDirSuffix)").join(core.hostOperatingSystem.imageFormat.executableName(basename: "UnitTestRunner")).str), arguments: ["--testing-library", "swift-testing"], environment: environment)
+                    #expect(String(decoding: executionResult.stderr, as: UTF8.self).contains("Test run with 1 test "))
+                }
+            }
+        }
+    }
+
     /// Check that environment variables are propagated from the user environment correctly.
     @Test(.requireSDKs(.host), .skipHostOS(.windows), .requireSystemPackages(apt: "yacc", yum: "byacc"))
     func userEnvironment() async throws {