diff --git a/pkg/front_end/test/fasta/suite_utils.dart b/pkg/front_end/test/fasta/suite_utils.dart
index dad2103d678..e45b3dfbef9 100644
--- a/pkg/front_end/test/fasta/suite_utils.dart
+++ b/pkg/front_end/test/fasta/suite_utils.dart
@@ -14,6 +14,8 @@ import 'package:testing/testing.dart' show Step, TestDescription;
 import '../coverage_helper.dart';
 import 'testing/suite.dart';
 
+const String limitToArgument = "--limitTo=";
+
 Future<void> internalMain(
   CreateContext createContext, {
   List<String> arguments = const [],
@@ -25,6 +27,7 @@ Future<void> internalMain(
   Logger logger = const StdoutLogger();
   List<String>? argumentsTrimmed;
   Uri? coverageUri;
+  int? limitTo;
   for (int i = 0; i < arguments.length; i++) {
     String argument = arguments[i];
     bool trimmed = false;
@@ -42,6 +45,9 @@ Future<void> internalMain(
       // Have this 1-indexed when given as an input.
       shard = int.parse(argument.substring("--shard=".length)) - 1;
       trimmed = true;
+    } else if (argument.startsWith(limitToArgument)) {
+      limitTo = int.tryParse(argument.substring(limitToArgument.length));
+      trimmed = true;
     }
 
     if (trimmed && argumentsTrimmed == null) {
@@ -63,6 +69,7 @@ Future<void> internalMain(
     configurationPath: configurationPath ?? "../../testing.json",
     shards: shards,
     shard: shard,
+    limitTo: limitTo,
     logger: logger,
   );
   if (coverageUri != null) {
diff --git a/pkg/front_end/test/flutter_gallery_leak_tester.dart b/pkg/front_end/test/flutter_gallery_leak_tester.dart
index 388e4f0d800..6f7019db5d2 100644
--- a/pkg/front_end/test/flutter_gallery_leak_tester.dart
+++ b/pkg/front_end/test/flutter_gallery_leak_tester.dart
@@ -158,6 +158,7 @@ Future<void> main(List<String> args) async {
     Uri.parse("package:kernel/ast.dart"),
     "Library",
     ["fileUri"],
+    expectToAlwaysFind: true,
   ));
   helper.VMServiceHeapHelperSpecificExactLeakFinder heapHelper =
       new helper.VMServiceHeapHelperSpecificExactLeakFinder(
@@ -167,6 +168,7 @@ Future<void> main(List<String> args) async {
         Uri.parse("package:kernel/ast.dart"),
         "Library",
         ["fileUri", "libraryIdForTesting"],
+        expectToAlwaysFind: true,
       ),
     ],
     throwOnPossibleLeak: true,
diff --git a/pkg/front_end/test/spell_checking_list_tests.txt b/pkg/front_end/test/spell_checking_list_tests.txt
index a4e59f26ca1..26e75a09be6 100644
--- a/pkg/front_end/test/spell_checking_list_tests.txt
+++ b/pkg/front_end/test/spell_checking_list_tests.txt
@@ -437,6 +437,7 @@ ing
 inhibit
 inlinable
 inlineable
+inoperable
 insights
 instrument
 instrumenter
diff --git a/pkg/front_end/test/vm_service_for_leak_detection.dart b/pkg/front_end/test/vm_service_for_leak_detection.dart
index 225994ba83f..87b15240b54 100644
--- a/pkg/front_end/test/vm_service_for_leak_detection.dart
+++ b/pkg/front_end/test/vm_service_for_leak_detection.dart
@@ -7,43 +7,9 @@ import 'dart:io';
 import "vm_service_heap_helper.dart" as helper;
 
 Future<void> main(List<String> args) async {
-  List<helper.Interest> interests = <helper.Interest>[];
-  interests.add(new helper.Interest(
-    Uri.parse("package:front_end/src/source/source_library_builder.dart"),
-    "SourceLibraryBuilder",
-    ["fileUri"],
-  ));
-  interests.add(new helper.Interest(
-    Uri.parse("package:front_end/src/source/source_extension_builder.dart"),
-    "SourceExtensionBuilder",
-    ["extension"],
-  ));
-  interests.add(new helper.Interest(
-    Uri.parse("package:kernel/ast.dart"),
-    "Library",
-    ["fileUri"],
-  ));
-  interests.add(new helper.Interest(
-    Uri.parse("package:kernel/ast.dart"),
-    "Extension",
-    ["name", "fileUri"],
-  ));
-
-  helper.VMServiceHeapHelperSpecificExactLeakFinder createNewLeakFinder() =>
-      new helper.VMServiceHeapHelperSpecificExactLeakFinder(
-        interests: interests,
-        prettyPrints: [
-          new helper.Interest(
-            Uri.parse("package:kernel/ast.dart"),
-            "Library",
-            ["fileUri", "libraryIdForTesting"],
-          ),
-        ],
-        throwOnPossibleLeak: true,
-      );
-
+  List<helper.Interest> interests = getInterests();
   helper.VMServiceHeapHelperSpecificExactLeakFinder heapHelper =
-      createNewLeakFinder();
+      createNewLeakFinder(interests);
 
   if (args.length > 0 && args[0] == "--dart2js") {
     await heapHelper.start([
@@ -79,7 +45,7 @@ Future<void> main(List<String> args) async {
           rethrow;
         }
         print("Will retry in a few seconds.");
-        heapHelper = createNewLeakFinder();
+        heapHelper = createNewLeakFinder(interests);
         await Future.delayed(const Duration(seconds: 2));
       }
     }
@@ -100,7 +66,7 @@ Future<void> main(List<String> args) async {
           rethrow;
         }
         print("Will retry in a few seconds.");
-        heapHelper = createNewLeakFinder();
+        heapHelper = createNewLeakFinder(interests);
         await Future.delayed(const Duration(seconds: 2));
       }
     }
@@ -114,3 +80,46 @@ Future<void> main(List<String> args) async {
     ]);
   }
 }
+
+helper.VMServiceHeapHelperSpecificExactLeakFinder createNewLeakFinder(
+    List<helper.Interest> interests) {
+  return new helper.VMServiceHeapHelperSpecificExactLeakFinder(
+    interests: interests,
+    prettyPrints: [
+      new helper.Interest(
+        Uri.parse("package:kernel/ast.dart"),
+        "Library",
+        ["fileUri", "libraryIdForTesting"],
+        expectToAlwaysFind: true,
+      ),
+    ],
+    throwOnPossibleLeak: true,
+  );
+}
+
+List<helper.Interest> getInterests() {
+  List<helper.Interest> interests = <helper.Interest>[];
+  interests.add(new helper.Interest(
+    Uri.parse("package:front_end/src/source/source_library_builder.dart"),
+    "SourceLibraryBuilder",
+    ["fileUri"],
+  ));
+  interests.add(new helper.Interest(
+    Uri.parse("package:front_end/src/source/source_extension_builder.dart"),
+    "SourceExtensionBuilder",
+    ["extension"],
+  ));
+  interests.add(new helper.Interest(
+    Uri.parse("package:kernel/ast.dart"),
+    "Library",
+    ["fileUri"],
+    expectToAlwaysFind: true,
+  ));
+  interests.add(new helper.Interest(
+    Uri.parse("package:kernel/ast.dart"),
+    "Extension",
+    ["name", "fileUri"],
+    expectToAlwaysFind: true,
+  ));
+  return interests;
+}
diff --git a/pkg/front_end/test/vm_service_for_leak_smoke_test.dart b/pkg/front_end/test/vm_service_for_leak_smoke_test.dart
new file mode 100644
index 00000000000..66eaa2bf812
--- /dev/null
+++ b/pkg/front_end/test/vm_service_for_leak_smoke_test.dart
@@ -0,0 +1,21 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:io';
+
+import 'fasta/suite_utils.dart' show limitToArgument;
+import "vm_service_for_leak_detection.dart" as helper;
+
+Future<void> main(List<String> args) async {
+  /// Run just a single test from the incremental suite (with finding leaks) to
+  /// verify that leak finding actually works and that - e.g. a move of kernel
+  /// stuff - makes it inoperable. Note that we require, for instance,
+  /// the Library class in the kernel ast to be found.
+  await helper.createNewLeakFinder(helper.getInterests()).start([
+    "--enable-asserts",
+    Platform.script.resolve("incremental_suite.dart").toString(),
+    "${limitToArgument}1",
+    "-DaddDebugBreaks=true",
+  ]);
+}
diff --git a/pkg/front_end/test/vm_service_heap_helper.dart b/pkg/front_end/test/vm_service_heap_helper.dart
index 66322d7a642..4f112eb1f66 100644
--- a/pkg/front_end/test/vm_service_heap_helper.dart
+++ b/pkg/front_end/test/vm_service_heap_helper.dart
@@ -7,10 +7,9 @@ import "vm_service_helper.dart" as vmService;
 class VMServiceHeapHelperSpecificExactLeakFinder
     extends vmService.LaunchingVMServiceHelper {
   final Set _interestsClassNames = {};
-  final Map<Uri, Map<String, List<String>>> _interests =
-      new Map<Uri, Map<String, List<String>>>();
-  final Map<Uri, Map<String, List<String>>> _prettyPrints =
-      new Map<Uri, Map<String, List<String>>>();
+  final Map<Uri, Map<String, List<String>>> _interests = {};
+  final Map<Uri, Map<String, List<String>>> _prettyPrints = {};
+  final Set<String> _shouldAlwaysFind = {};
   final bool throwOnPossibleLeak;
   bool verbose = false;
   int? timeout;
@@ -22,6 +21,9 @@ class VMServiceHeapHelperSpecificExactLeakFinder
   }) {
     if (interests.isEmpty) throw "Empty list of interests given";
     for (Interest interest in interests) {
+      if (interest.expectToAlwaysFind) {
+        _shouldAlwaysFind.add("${interest.uri}|${interest.className}");
+      }
       Map<String, List<String>>? classToFields = _interests[interest.uri];
       if (classToFields == null) {
         classToFields = Map<String, List<String>>();
@@ -124,28 +126,34 @@ class VMServiceHeapHelperSpecificExactLeakFinder
 
       stopwatch.reset();
       List<Leak> leaks = [];
+      Set<String> leftToAlwaysFind = _shouldAlwaysFind.toSet();
       for (vmService.ClassHeapStats member in allocationProfile.members!) {
         if (_interestsClassNames.contains(member.classRef!.name)) {
+          String? libraryId = member.classRef?.library?.id;
+          if (libraryId == null) continue;
+          vmService.Library library = (await serviceClient.getObject(
+              _isolateRef.id!, libraryId)) as vmService.Library;
+          String? importUriString = library.uri;
+          if (importUriString == null) continue;
+          String? classId = member.classRef?.id;
+          if (classId == null) continue;
           vmService.Class c = (await serviceClient.getObject(
-              _isolateRef.id!, member.classRef!.id!)) as vmService.Class;
-          String? uriString = c.location?.script?.uri;
-          if (uriString == null) continue;
-          Uri uri = Uri.parse(uriString);
-          Map<String, List<String>>? uriInterest = _interests[uri];
-          if (uriInterest == null) continue;
-          List<String>? fieldsForClass = uriInterest[c.name];
-          if (fieldsForClass == null) continue;
+              _isolateRef.id!, classId)) as vmService.Class;
+          String? partUriString = c.location?.script?.uri;
+          if (partUriString == null) continue;
+          String? className = c.name;
+          if (className == null) continue;
 
-          List<String> fieldsForClassPrettyPrint = fieldsForClass;
-
-          uriInterest = _prettyPrints[uri];
-          if (uriInterest != null) {
-            if (uriInterest[c.name] != null) {
-              fieldsForClassPrettyPrint = uriInterest[c.name]!;
-            }
-          }
+          (List<String>, List<String>)? fieldsData =
+              _getFieldsForClassAndPrettyPrint(partUriString, className) ??
+                  _getFieldsForClassAndPrettyPrint(importUriString, className);
+          if (fieldsData == null) continue;
+          List<String> fieldsForClass = fieldsData.$1;
+          List<String> fieldsForClassPrettyPrint = fieldsData.$2;
 
           if (member.instancesCurrent != 0) {
+            leftToAlwaysFind.remove("$partUriString|$className");
+            leftToAlwaysFind.remove("$importUriString|$className");
             if (verbose) {
               print("Has ${member.instancesCurrent} instances of "
                   "${member.classRef!.name}");
@@ -166,6 +174,9 @@ class VMServiceHeapHelperSpecificExactLeakFinder
       } else {
         noLeakDetected();
       }
+      if (leftToAlwaysFind.isNotEmpty) {
+        throw "Expected to find, but didn't: $leftToAlwaysFind";
+      }
 
       print("Looked for leaks in ${stopwatch.elapsedMilliseconds} ms");
 
@@ -181,6 +192,22 @@ class VMServiceHeapHelperSpecificExactLeakFinder
     }
   }
 
+  (List<String>, List<String>)? _getFieldsForClassAndPrettyPrint(
+      String uriString, String className) {
+    Uri uri = Uri.parse(uriString);
+    Map<String, List<String>>? uriInterest = _interests[uri];
+    if (uriInterest == null) return null;
+    List<String>? fieldsForClass = uriInterest[className];
+    if (fieldsForClass == null) return null;
+
+    List<String> fieldsForClassPrettyPrint = fieldsForClass;
+    uriInterest = _prettyPrints[uri];
+    if (uriInterest != null && uriInterest[className] != null) {
+      fieldsForClassPrettyPrint = uriInterest[className]!;
+    }
+    return (fieldsForClass, fieldsForClassPrettyPrint);
+  }
+
   Future<List<Leak>> _findLeaks(
       vmService.IsolateRef isolateRef,
       vmService.ClassRef classRef,
@@ -364,8 +391,10 @@ class Interest {
   final Uri uri;
   final String className;
   final List<String> fieldNames;
+  final bool expectToAlwaysFind;
 
-  Interest(this.uri, this.className, this.fieldNames);
+  Interest(this.uri, this.className, this.fieldNames,
+      {this.expectToAlwaysFind = false});
 }
 
 class Leak {
diff --git a/pkg/front_end/test/vm_service_heap_helper_test.dart b/pkg/front_end/test/vm_service_heap_helper_test.dart
index 3879d8894da..fc1f03f2fa8 100644
--- a/pkg/front_end/test/vm_service_heap_helper_test.dart
+++ b/pkg/front_end/test/vm_service_heap_helper_test.dart
@@ -15,6 +15,14 @@ Future<void> main(List<String> args) async {
     return doLeak();
   }
 
+  await findsExpectedLeakData();
+  await doesNotThrowsWhenNotFindingIfShouldNotAlwaysBeFound();
+  await throwsWhenNotFindingWhatShouldAlwaysBeFound();
+
+  print("Done!");
+}
+
+Future<void> findsExpectedLeakData() async {
   List<helper.Interest> interests = <helper.Interest>[];
   interests.add(
     new helper.Interest(
@@ -37,6 +45,7 @@ Future<void> main(List<String> args) async {
         Platform.script,
         "LeakMe",
         ["unique", "forPrettyPrinting"],
+        expectToAlwaysFind: true,
       ),
       new helper.Interest(
         Platform.script,
@@ -78,8 +87,96 @@ Future<void> main(List<String> args) async {
         "vs\n\n"
         "- ${leakData.join("\n- ")}";
   }
+}
 
-  print("Done!");
+Future<void> doesNotThrowsWhenNotFindingIfShouldNotAlwaysBeFound() async {
+  List<helper.Interest> interests = <helper.Interest>[];
+  interests.add(
+    // A class called "LeakMeSpellingError" doesn't exist. But we don't say we
+    // expect to find it so it doesn't throw.
+    new helper.Interest(
+      Platform.script,
+      "LeakMeSpellingError",
+      ["unique"],
+    ),
+  );
+  LeakFinderTest heapHelper = new LeakFinderTest(
+    interests: interests,
+    prettyPrints: const [],
+    throwOnPossibleLeak: false,
+  );
+
+  List<({dynamic error, StackTrace st})> errors =
+      await runAndGetErrors(() async {
+    await heapHelper.start(
+      [
+        "--enable-asserts",
+        Platform.script.toString(),
+        "--leak",
+      ],
+      stderrReceiver: (s) {},
+      stdoutReceiver: (s) {},
+    );
+    return heapHelper.completer.future;
+  });
+
+  // Run is now over. Verify we got the wanted error.
+  if (errors.length != 0) {
+    throw "Expected 0 error, got ${errors.length}: $errors";
+  }
+}
+
+Future<void> throwsWhenNotFindingWhatShouldAlwaysBeFound() async {
+  List<helper.Interest> interests = <helper.Interest>[];
+  interests.add(
+    // Expect to find a class called "LeakMeSpellingError" --- but it doesn't
+    // exist so it won't. It should thus throw because "expectToAlwaysFind" is
+    // true.
+    new helper.Interest(
+      Platform.script,
+      "LeakMeSpellingError",
+      ["unique"],
+      expectToAlwaysFind: true,
+    ),
+  );
+  LeakFinderTest heapHelper = new LeakFinderTest(
+    interests: interests,
+    prettyPrints: const [],
+    throwOnPossibleLeak: false,
+  );
+
+  List<({dynamic error, StackTrace st})> errors =
+      await runAndGetErrors(() async {
+    await heapHelper.start(
+      [
+        "--enable-asserts",
+        Platform.script.toString(),
+        "--leak",
+      ],
+      stderrReceiver: (s) {},
+      stdoutReceiver: (s) {},
+    );
+    return heapHelper.completer.future;
+  });
+
+  // Run is now over. Verify we got the wanted error.
+  if (errors.length != 1 ||
+      !errors[0].error.toString().contains("Expected to find, but didn't")) {
+    throw "Expected 1 error, got ${errors.length}: $errors";
+  }
+}
+
+Future<List<({dynamic error, StackTrace st})>> runAndGetErrors(
+    Future Function() f) async {
+  List<({dynamic error, StackTrace st})> errors = [];
+  await runZoned(() {
+    return f();
+  }, zoneSpecification: ZoneSpecification(
+    handleUncaughtError: (self, parent, zone, error, stackTrace) {
+      errors.add((error: error, st: stackTrace));
+    },
+  ));
+  return errors;
 }
 
 void doLeak() {
diff --git a/pkg/testing/lib/src/chain.dart b/pkg/testing/lib/src/chain.dart
index aead8550835..55037c4a148 100644
--- a/pkg/testing/lib/src/chain.dart
+++ b/pkg/testing/lib/src/chain.dart
@@ -118,6 +118,7 @@ abstract class ChainContext {
   Future<void> run(Chain suite, Set<String> selectors,
       {int shards = 1,
       int shard = 0,
+      int? limitTo,
       Logger logger = const StdoutLogger()}) async {
     assert(shards >= 1, "Invalid shards count: $shards");
     assert(0 <= shard && shard < shards,
@@ -147,6 +148,9 @@ abstract class ChainContext {
       }
       descriptions = shardDescriptions;
     }
+    if (limitTo != null && limitTo > 0 && limitTo < descriptions.length) {
+      descriptions = descriptions.sublist(0, limitTo);
+    }
     Map<TestDescription, Result> unexpectedResults =
         <TestDescription, Result>{};
     Map<TestDescription, Set<Expectation>> unexpectedOutcomes =
diff --git a/pkg/testing/lib/src/run.dart b/pkg/testing/lib/src/run.dart
index bd5e66efe5e..cb3e571f3f2 100644
--- a/pkg/testing/lib/src/run.dart
+++ b/pkg/testing/lib/src/run.dart
@@ -51,6 +51,7 @@ Future<void> runMe(List<String> arguments, CreateContext f,
     Uri? me,
     int shards = 1,
     int shard = 0,
+    int? limitTo,
     Logger logger = const StdoutLogger()}) {
   me ??= Platform.script;
   return withErrorHandling(() async {
@@ -61,7 +62,7 @@ Future<void> runMe(List<String> arguments, CreateContext f,
       if (me == suite.source) {
         ChainContext context = await f(suite, cl.environment);
         await context.run(suite, Set<String>.from(cl.selectors),
-            shards: shards, shard: shard, logger: logger);
+            shards: shards, shard: shard, limitTo: limitTo, logger: logger);
       }
     }
   }, logger: logger);