 
   /// Ensure that the driver can detect and then recover from a priors version mismatch
   func testPriorsVersionDetectionAndRecovery() throws {
-#if !os(Linux)
+#if _runtime(_ObjC)
     // create a baseline priors
     try buildInitialState(checkDiagnostics: true)
     let driver = try checkNullBuild(checkDiagnostics: true)


  /// Ensure that a saved prior module dependency graph is rejected if not from the previous build
  func testObsoletePriors() throws {
#if !os(Linux)
    let before = Date().advanced(by: -2.0)
    let driver = try buildInitialState(checkDiagnostics: true)
    let path = try XCTUnwrap(driver.buildRecordInfo?.dependencyGraphPath)


extension IncrementalCompilationTests {
  func testRemoval() throws {
#if _runtime(_ObjC)
    for optionsToTest in RemovalTestOptions.allCombinations {
      try testRemoval(optionsToTest)
    }
