diff --git a/build_runner/CHANGELOG.md b/build_runner/CHANGELOG.md
index 1ef84f6aa1..7c0dfb6364 100644
--- a/build_runner/CHANGELOG.md
+++ b/build_runner/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 2.9.1-wip
+
+- Internal changes for `build_test`.
+
 ## 2.9.0
 
 - Watch mode: handle builder code and config changes without recompiling or
diff --git a/build_runner/lib/src/build/build.dart b/build_runner/lib/src/build/build.dart
index 8f5b9f72c8..eaec366f64 100644
--- a/build_runner/lib/src/build/build.dart
+++ b/build_runner/lib/src/build/build.dart
@@ -190,9 +190,11 @@ class Build {
     }
 
     _resolvers.reset();
-    buildLog.finishBuild(
-      result: result.status == BuildStatus.success,
-      outputs: result.outputs.length,
+    result = result.copyWith(
+      errors: buildLog.finishBuild(
+        result: result.status == BuildStatus.success,
+        outputs: result.outputs.length,
+      ),
     );
     return result;
   }
diff --git a/build_runner/lib/src/build/build_result.dart b/build_runner/lib/src/build/build_result.dart
index 9d859abec0..2edb8d849e 100644
--- a/build_runner/lib/src/build/build_result.dart
+++ b/build_runner/lib/src/build/build_result.dart
@@ -18,6 +18,9 @@ class BuildResult {
   /// The type of failure.
   final FailureType? failureType;
 
+  /// Errors reported.
+  final BuiltList<String> errors;
+
   /// All outputs created/updated during this build.
   final BuiltList<AssetId> outputs;
 
@@ -30,6 +33,7 @@ class BuildResult {
 
   BuildResult({
     required this.status,
+    BuiltList<String>? errors,
     BuiltList<AssetId>? outputs,
     required this.buildOutputReader,
     this.performance,
@@ -38,16 +42,21 @@ class BuildResult {
            failureType == null && status == BuildStatus.failure
                ? FailureType.general
                : failureType,
+       errors = errors ?? BuiltList(),
        outputs = outputs ?? BuiltList();
 
-  BuildResult copyWith({BuildStatus? status, FailureType? failureType}) =>
-      BuildResult(
-        status: status ?? this.status,
-        outputs: outputs,
-        buildOutputReader: buildOutputReader,
-        performance: performance,
-        failureType: failureType ?? this.failureType,
-      );
+  BuildResult copyWith({
+    BuildStatus? status,
+    FailureType? failureType,
+    BuiltList<String>? errors,
+  }) => BuildResult(
+    status: status ?? this.status,
+    errors: errors ?? this.errors,
+    outputs: outputs,
+    buildOutputReader: buildOutputReader,
+    performance: performance,
+    failureType: failureType ?? this.failureType,
+  );
 
   @override
   String toString() {
diff --git a/build_runner/lib/src/logging/build_log.dart b/build_runner/lib/src/logging/build_log.dart
index 72a6bcaf38..94537be092 100644
--- a/build_runner/lib/src/logging/build_log.dart
+++ b/build_runner/lib/src/logging/build_log.dart
@@ -5,6 +5,7 @@
 import 'dart:math';
 
 import 'package:build/build.dart' show AssetId;
+import 'package:built_collection/built_collection.dart';
 
 import '../bootstrap/build_process_state.dart';
 import '../build_plan/phase.dart';
@@ -67,6 +68,9 @@ class BuildLog {
   /// The messages logged, bucketed by build phase.
   final BuildLogMessages _messages = BuildLogMessages();
 
+  /// Errors logged.
+  final ListBuilder<String> _errors = ListBuilder();
+
   /// Progress by build phase.
   final Map<String, _PhaseProgress> _phaseProgress = {};
 
@@ -167,6 +171,7 @@ class BuildLog {
 
   /// Logs an `build_runner` error.
   void error(String message) {
+    _errors.add(message);
     if (_display.displayingBlocks) {
       _messages.add(severity: Severity.error, message);
       _display.block(render());
@@ -182,6 +187,7 @@ class BuildLog {
     String? phaseName,
     String? context,
   }) {
+    if (severity == Severity.error) _errors.add(message);
     if (_display.displayingBlocks) {
       _messages.add(
         severity: severity,
@@ -339,7 +345,9 @@ class BuildLog {
   }
 
   /// Logs that the build has finished with [result] and the count of [outputs].
-  void finishBuild({required bool result, required int outputs}) {
+  ///
+  /// Returns the list of errors logged.
+  BuiltList<String> finishBuild({required bool result, required int outputs}) {
     _tick();
     final displayingBlocks = _display.displayingBlocks;
     _status = [
@@ -362,6 +370,10 @@ class BuildLog {
         AnsiBufferLine(_status).toString(),
       );
     }
+
+    final errors = _errors.build();
+    _errors.clear();
+    return errors;
   }
 
   /// Renders [message] with optional [error] and [stackTrace].
diff --git a/build_runner/pubspec.yaml b/build_runner/pubspec.yaml
index c2c15f8f10..ae533cd8c3 100644
--- a/build_runner/pubspec.yaml
+++ b/build_runner/pubspec.yaml
@@ -1,5 +1,5 @@
 name: build_runner
-version: 2.9.0
+version: 2.9.1-wip
 description: A build system for Dart code generation and modular compilation.
 repository: https://github.com/dart-lang/build/tree/master/build_runner
 resolution: workspace
diff --git a/build_runner/test/build/build_error_test.dart b/build_runner/test/build/build_error_test.dart
index af51ad467b..254bec614e 100644
--- a/build_runner/test/build/build_error_test.dart
+++ b/build_runner/test/build/build_error_test.dart
@@ -5,7 +5,6 @@
 import 'dart:async';
 
 import 'package:build/build.dart';
-import 'package:build_runner/src/build/build_result.dart';
 import 'package:build_test/build_test.dart';
 import 'package:logging/logging.dart';
 import 'package:test/test.dart';
@@ -14,14 +13,13 @@ import '../common/common.dart';
 
 void main() {
   test('should fail if a severe logged', () async {
-    expect(
-      (await testBuilders(
-        [_LoggingBuilder(Level.SEVERE)],
-        {'a|lib/a.dart': ''},
-        outputs: {'a|lib/a.dart.empty': ''},
-      )).buildResult.status,
-      BuildStatus.failure,
+    final result = await testBuilders(
+      [_LoggingBuilder(Level.SEVERE)],
+      {'a|lib/a.dart': ''},
+      outputs: {'a|lib/a.dart.empty': ''},
     );
+    expect(result.succeeded, false);
+    expect(result.errors, ['Log message for a|lib/a.dart.']);
   });
 
   test('should fail if a severe was logged on a previous build', () async {
@@ -30,7 +28,8 @@ void main() {
       {'a|lib/a.dart': ''},
       outputs: {'a|lib/a.dart.empty': ''},
     );
-    expect(result.buildResult.status, BuildStatus.failure);
+    expect(result.succeeded, false);
+    expect(result.errors, ['Log message for a|lib/a.dart.']);
 
     final builder = _LoggingBuilder(Level.SEVERE);
     result = await testBuilders(
@@ -40,7 +39,8 @@ void main() {
       readerWriter: result.readerWriter,
       outputs: {'a|lib/a.dart.empty': ''},
     );
-    expect(result.buildResult.status, BuildStatus.failure);
+    expect(result.succeeded, false);
+    expect(result.errors, ['Log message for a|lib/a.dart.']);
     // Should have failed without actually building again.
     expect(builder.built, false);
   });
@@ -53,7 +53,8 @@ void main() {
         {'a|lib/a.dart': ''},
         outputs: {'a|lib/a.dart.empty': ''},
       );
-      expect(result.buildResult.status, BuildStatus.failure);
+      expect(result.succeeded, false);
+      expect(result.errors, ['Log message for a|lib/a.dart.']);
 
       result = await testBuilders(
         [_LoggingBuilder(Level.WARNING)],
@@ -62,18 +63,18 @@ void main() {
         readerWriter: result.readerWriter,
         outputs: {'a|lib/a.dart.empty': ''},
       );
-      expect(result.buildResult.status, BuildStatus.success);
+      expect(result.succeeded, true);
+      expect(result.errors, isEmpty);
     },
   );
 
   test('should fail if an exception is thrown', () async {
-    expect(
-      (await testBuilders(
-        [TestBuilder(build: (_, _) => throw Exception('Some build failure'))],
-        {'a|lib/a.txt': ''},
-      )).buildResult.status,
-      BuildStatus.failure,
+    final result = await testBuilders(
+      [TestBuilder(build: (_, _) => throw Exception('Some build failure'))],
+      {'a|lib/a.txt': ''},
     );
+    expect(result.succeeded, false);
+    expect(result.errors, ['Exception: Some build failure']);
   });
 
   test(
@@ -110,7 +111,8 @@ void main() {
         ],
         {'a|lib/a.txt': ''},
       );
-      expect(result.buildResult.status, BuildStatus.failure);
+      expect(result.succeeded, false);
+      expect(result.errors, ['Wrote an output then failed']);
     },
   );
 }
@@ -124,7 +126,7 @@ class _LoggingBuilder implements Builder {
   @override
   Future<void> build(BuildStep buildStep) async {
     built = true;
-    log.log(level, buildStep.inputId.toString());
+    log.log(level, 'Log message for ${buildStep.inputId}.');
     await buildStep.canRead(buildStep.inputId);
     await buildStep.writeAsString(buildStep.inputId.addExtension('.empty'), '');
   }
diff --git a/build_runner/test/build/build_test.dart b/build_runner/test/build/build_test.dart
index 02b17605ea..49e0b73caa 100644
--- a/build_runner/test/build/build_test.dart
+++ b/build_runner/test/build/build_test.dart
@@ -889,8 +889,8 @@ targets:
         (await testBuilders(
           [TestBuilder(build: copyFrom(makeAssetId('a|.dart_tool/any_file')))],
           {'a|lib/a.txt': 'a', 'a|.dart_tool/any_file': 'content'},
-        )).buildResult.status,
-        BuildStatus.failure,
+        )).succeeded,
+        false,
       );
     });
 
diff --git a/build_runner/test/build/write_cache_test.dart b/build_runner/test/build/write_cache_test.dart
index 7ec65160d9..a2a84cb625 100644
--- a/build_runner/test/build/write_cache_test.dart
+++ b/build_runner/test/build/write_cache_test.dart
@@ -5,7 +5,6 @@
 import 'dart:async';
 
 import 'package:build/build.dart';
-import 'package:build_runner/src/build/build_result.dart';
 import 'package:build_test/build_test.dart';
 import 'package:test/test.dart';
 
@@ -25,7 +24,7 @@ void main() {
       readerWriter: readerWriter,
       enableLowResourceMode: true,
     );
-    expect(result.buildResult.status, BuildStatus.success);
+    expect(result.succeeded, true);
   });
 
   test('with caching writes wait until build completion', () async {
@@ -40,7 +39,7 @@ void main() {
       readerWriter: readerWriter,
       enableLowResourceMode: false,
     );
-    expect(result.buildResult.status, BuildStatus.success);
+    expect(result.succeeded, true);
     expect(
       readerWriter.testing.assets,
       containsAll([
@@ -66,7 +65,7 @@ void main() {
       readerWriter: readerWriter,
       enableLowResourceMode: false,
     );
-    expect(result.buildResult.status, BuildStatus.success);
+    expect(result.succeeded, true);
   });
 }
 
diff --git a/build_runner/test/build_plan/build_triggers_test.dart b/build_runner/test/build_plan/build_triggers_test.dart
index 67aade4700..129e54805f 100644
--- a/build_runner/test/build_plan/build_triggers_test.dart
+++ b/build_runner/test/build_plan/build_triggers_test.dart
@@ -6,7 +6,6 @@ import 'package:analyzer/dart/analysis/utilities.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:build/build.dart';
 import 'package:build_config/build_config.dart';
-import 'package:build_runner/src/build/build_result.dart';
 import 'package:build_runner/src/build_plan/build_triggers.dart';
 import 'package:build_test/build_test.dart';
 import 'package:test/test.dart';
@@ -250,7 +249,7 @@ triggers:
         outputs: {},
         testingBuilderConfig: false,
       );
-      expect(result.buildResult.status, BuildStatus.success);
+      expect(result.succeeded, true);
     });
 
     test('trigger builder in same file', () async {
@@ -295,7 +294,7 @@ triggers:
         outputs: {},
         testingBuilderConfig: false,
       );
-      expect(result.buildResult.status, BuildStatus.success);
+      expect(result.succeeded, true);
     });
 
     test('trigger builder in part file', () async {
diff --git a/build_test/CHANGELOG.md b/build_test/CHANGELOG.md
index 93189390a2..fa5e75b97a 100644
--- a/build_test/CHANGELOG.md
+++ b/build_test/CHANGELOG.md
@@ -1,3 +1,10 @@
+## 3.5.0-wip
+
+- Improve `TestBuilderResult`: add `succeeded`, `outputs` and `errors`.
+  Deprecate `buildResult` in favor of these new members.
+- Add `verbose` to `testBuilders` and related methods. Like the command line
+  flag it enables info logging from builders.
+
 ## 3.4.1
 
 - Use `build_runner` 2.9.0.
diff --git a/build_test/lib/src/test_builder.dart b/build_test/lib/src/test_builder.dart
index e121086c0d..1ff44e0c41 100644
--- a/build_test/lib/src/test_builder.dart
+++ b/build_test/lib/src/test_builder.dart
@@ -137,6 +137,7 @@ Future<TestBuilderResult> testBuilder(
   PackageConfig? packageConfig,
   Resolvers? resolvers,
   TestReaderWriter? readerWriter,
+  bool verbose = false,
   bool enableLowResourceMode = false,
 }) async {
   return testBuilders(
@@ -151,6 +152,7 @@ Future<TestBuilderResult> testBuilder(
     packageConfig: packageConfig,
     resolvers: resolvers,
     readerWriter: readerWriter,
+    verbose: verbose,
     enableLowResourceMode: enableLowResourceMode,
   );
 }
@@ -182,6 +184,7 @@ Future<TestBuilderResult> testBuilders(
   Map<Builder, List<String>> appliesBuilders = const {},
   bool testingBuilderConfig = true,
   TestReaderWriter? readerWriter,
+  bool verbose = false,
   bool enableLowResourceMode = false,
 }) {
   final builderFactories = <BuilderFactory>[];
@@ -222,6 +225,7 @@ Future<TestBuilderResult> testBuilders(
     appliesBuilders: appliesBuildersToFactories,
     testingBuilderConfig: testingBuilderConfig,
     readerWriter: readerWriter,
+    verbose: verbose,
     enableLowResourceMode: enableLowResourceMode,
   );
 }
@@ -283,6 +287,9 @@ Future<TestBuilderResult> testBuilders(
 /// Optionally pass [readerWriter] to set the filesystem that will be used
 /// during the build. Before the build, [sourceAssets] will be written to it.
 ///
+/// Optionally pass [verbose], which acts like the command line flag: it enables
+/// info logging from builders.
+///
 /// Optionally pass [enableLowResourceMode], which acts like the command
 /// line flag; in particular it disables file caching.
 ///
@@ -306,6 +313,7 @@ Future<TestBuilderResult> testBuilderFactories(
   Map<BuilderFactory, List<String>> appliesBuilders = const {},
   bool testingBuilderConfig = true,
   TestReaderWriter? readerWriter,
+  bool verbose = false,
   bool enableLowResourceMode = false,
 }) async {
   onLog ??= _printOnFailureOrWrite;
@@ -352,6 +360,7 @@ Future<TestBuilderResult> testBuilderFactories(
 
   buildLog.configuration = buildLog.configuration.rebuild((b) {
     b.onLog = onLog;
+    b.verbose = verbose;
   });
   resolvers ??=
       packageConfig == null && enabledExperiments.isEmpty
@@ -459,6 +468,7 @@ Future<TestBuilderResult> testBuilderFactories(
     // ignore: invalid_use_of_visible_for_testing_member
     buildOptions: BuildOptions.forTests(
       enableLowResourcesMode: enableLowResourceMode,
+      verbose: verbose,
     ),
     testingOverrides: testingOverrides,
   );
@@ -487,9 +497,23 @@ Future<TestBuilderResult> testBuilderFactories(
 }
 
 class TestBuilderResult {
+  @Deprecated('Use `succeeded`, `outputs` and `errors` instead.')
   final BuildResult buildResult;
   final TestReaderWriter readerWriter;
 
+  bool get succeeded => buildResult.status == BuildStatus.success;
+
+  /// The files that were written.
+  ///
+  /// If the build was an incremental build, outputs of the previous build that
+  /// are reused are _not_ included here.
+  BuiltList<AssetId> get outputs => buildResult.outputs;
+
+  /// The errors that were shown.
+  ///
+  /// If the build failed there must be at least one error.
+  BuiltList<String> get errors => buildResult.errors;
+
   TestBuilderResult({required this.buildResult, required this.readerWriter});
 }
 
diff --git a/build_test/pubspec.yaml b/build_test/pubspec.yaml
index 315a8b09fd..9e9ff45b12 100644
--- a/build_test/pubspec.yaml
+++ b/build_test/pubspec.yaml
@@ -1,6 +1,6 @@
 name: build_test
 description: Utilities for writing unit tests of Builders.
-version: 3.4.1
+version: 3.5.0-wip
 repository: https://github.com/dart-lang/build/tree/master/build_test
 resolution: workspace
 
@@ -10,7 +10,7 @@ environment:
 dependencies:
   build: '4.0.1'
   build_config: ^1.0.0
-  build_runner: '2.9.0'
+  build_runner: '2.9.1-wip'
   built_collection: ^5.1.1
   crypto: ^3.0.0
   glob: ^2.0.0
diff --git a/build_test/test/test_builder_test.dart b/build_test/test/test_builder_test.dart
index f06d865dce..63349b695a 100644
--- a/build_test/test/test_builder_test.dart
+++ b/build_test/test/test_builder_test.dart
@@ -394,6 +394,95 @@ import 'package:glob/glob.dart';
     );
     expect(logs, isEmpty);
   });
+
+  test('info messages are not logged, warnings are', () async {
+    final logs = <String>[];
+    await testBuilders(
+      [
+        TestBuilder(
+          build: (buildStep, _) async {
+            log.info('not logged by default');
+            log.warning('is logged by default');
+          },
+          buildExtensions: {
+            '.dart': ['.g.dart'],
+          },
+        ),
+      ],
+      {'test_package|lib/a.dart': ''},
+      onLog: (record) {
+        logs.add(record.toString());
+      },
+    );
+    expect(logs.join('\n'), isNot(contains('not logged by default')));
+    expect(logs.join('\n'), contains('is logged by default'));
+  });
+
+  test('info messages are logged if `verbose`', () async {
+    final logs = <String>[];
+    await testBuilders(
+      [
+        TestBuilder(
+          build: (buildStep, _) async {
+            log.info('is now logged');
+          },
+          buildExtensions: {
+            '.dart': ['.g.dart'],
+          },
+        ),
+      ],
+      {'test_package|lib/a.dart': ''},
+      onLog: (record) {
+        logs.add(record.toString());
+      },
+      verbose: true,
+    );
+    expect(logs.join('\n'), contains('is now logged'));
+  });
+
+  test('severe messages are logged and returned as errors', () async {
+    final logs = <String>[];
+    final result = await testBuilders(
+      [
+        TestBuilder(
+          build: (buildStep, _) async {
+            log.severe('some error');
+          },
+          buildExtensions: {
+            '.dart': ['.g.dart'],
+          },
+        ),
+      ],
+      {'test_package|lib/a.dart': ''},
+      onLog: (record) {
+        if (record.level == Level.SEVERE) logs.add(record.toString());
+      },
+    );
+    expect(logs.join('\n'), contains('some error'));
+    expect(result.errors.join('\n'), contains('some error'));
+  });
+
+  test('exceptions are logged and returned as errors', () async {
+    final logs = <String>[];
+    final result = await testBuilders(
+      [
+        TestBuilder(
+          build: (buildStep, _) async {
+            throw Exception('some exception');
+          },
+          buildExtensions: {
+            '.dart': ['.g.dart'],
+          },
+        ),
+      ],
+      {'test_package|lib/a.dart': ''},
+      onLog: (record) {
+        if (record.level == Level.SEVERE) logs.add(record.toString());
+      },
+    );
+    expect(logs.join('\n'), contains('Exception: some exception'));
+    expect(result.errors.join('\n'), contains('Exception: some exception'));
+  });
 }
 
 /// Concatenates the contents of multiple text files into a single output.