diff --git a/packages/flutter_tools/lib/src/cache.dart b/packages/flutter_tools/lib/src/cache.dart
index e997b3fdbfa..a54197f4f31 100644
--- a/packages/flutter_tools/lib/src/cache.dart
+++ b/packages/flutter_tools/lib/src/cache.dart
@@ -700,8 +700,6 @@ class PubDependencies extends ArtifactSet {
       context: PubContext.pubGet,
       directory: _fileSystem.path.join(_flutterRoot(), 'packages', 'flutter_tools'),
       generateSyntheticPackage: false,
-      skipPubspecYamlCheck: true,
-      checkLastModified: false,
     );
   }
 }
diff --git a/packages/flutter_tools/lib/src/commands/packages.dart b/packages/flutter_tools/lib/src/commands/packages.dart
index d31b337a15f..ef8c625b702 100644
--- a/packages/flutter_tools/lib/src/commands/packages.dart
+++ b/packages/flutter_tools/lib/src/commands/packages.dart
@@ -117,7 +117,6 @@ class PackagesGetCommand extends FlutterCommand {
         directory: directory,
         upgrade: upgrade ,
         offline: boolArg('offline'),
-        checkLastModified: false,
         generateSyntheticPackage: flutterProject.manifest.generateSyntheticPackage,
       );
       pubGetTimer.stop();
diff --git a/packages/flutter_tools/lib/src/commands/test.dart b/packages/flutter_tools/lib/src/commands/test.dart
index 6724b450fdf..12a32b516e0 100644
--- a/packages/flutter_tools/lib/src/commands/test.dart
+++ b/packages/flutter_tools/lib/src/commands/test.dart
@@ -8,11 +8,8 @@ import '../asset.dart';
 import '../base/common.dart';
 import '../base/file_system.dart';
 import '../build_info.dart';
-import '../build_system/build_system.dart';
 import '../bundle.dart';
 import '../cache.dart';
-import '../dart/generate_synthetic_packages.dart';
-import '../dart/pub.dart';
 import '../devfs.dart';
 import '../globals.dart' as globals;
 import '../project.dart';
@@ -169,32 +166,6 @@ class TestCommand extends FlutterCommand {
         'directory (or one of its subdirectories).');
     }
     final FlutterProject flutterProject = FlutterProject.current();
-    if (shouldRunPub) {
-      if (flutterProject.manifest.generateSyntheticPackage) {
-        final Environment environment = Environment(
-          artifacts: globals.artifacts,
-          logger: globals.logger,
-          cacheDir: globals.cache.getRoot(),
-          engineVersion: globals.flutterVersion.engineRevision,
-          fileSystem: globals.fs,
-          flutterRootDir: globals.fs.directory(Cache.flutterRoot),
-          outputDir: globals.fs.directory(getBuildDirectory()),
-          processManager: globals.processManager,
-          projectDir: flutterProject.directory,
-        );
-
-        await generateLocalizationsSyntheticPackage(
-          environment: environment,
-          buildSystem: globals.buildSystem,
-        );
-      }
-
-      await pub.get(
-        context: PubContext.getVerifyContext(name),
-        skipPubspecYamlCheck: true,
-        generateSyntheticPackage: flutterProject.manifest.generateSyntheticPackage,
-      );
-    }
     final bool buildTestAssets = boolArg('test-assets');
     final List<String> names = stringsArg('name');
     final List<String> plainNames = stringsArg('plain-name');
diff --git a/packages/flutter_tools/lib/src/commands/update_packages.dart b/packages/flutter_tools/lib/src/commands/update_packages.dart
index e30cc56f466..16cf2524d61 100644
--- a/packages/flutter_tools/lib/src/commands/update_packages.dart
+++ b/packages/flutter_tools/lib/src/commands/update_packages.dart
@@ -330,7 +330,6 @@ class UpdatePackagesCommand extends FlutterCommand {
           context: PubContext.updatePackages,
           directory: tempDir.path,
           upgrade: true,
-          checkLastModified: false,
           offline: offline,
           flutterRootOverride: upgrade
             ? temporaryFlutterSdk.path
@@ -413,7 +412,6 @@ class UpdatePackagesCommand extends FlutterCommand {
       await pub.get(
         context: PubContext.updatePackages,
         directory: dir.path,
-        checkLastModified: false,
         offline: offline,
         generateSyntheticPackage: false,
       );
diff --git a/packages/flutter_tools/lib/src/commands/upgrade.dart b/packages/flutter_tools/lib/src/commands/upgrade.dart
index 39177ebfece..986d776f20a 100644
--- a/packages/flutter_tools/lib/src/commands/upgrade.dart
+++ b/packages/flutter_tools/lib/src/commands/upgrade.dart
@@ -296,7 +296,6 @@ class UpgradeCommandRunner {
         context: PubContext.pubUpgrade,
         directory: projectRoot,
         upgrade: true,
-        checkLastModified: false,
         generateSyntheticPackage: false,
       );
     }
diff --git a/packages/flutter_tools/lib/src/commands/version.dart b/packages/flutter_tools/lib/src/commands/version.dart
index 72a33524d3c..717d09e6b75 100644
--- a/packages/flutter_tools/lib/src/commands/version.dart
+++ b/packages/flutter_tools/lib/src/commands/version.dart
@@ -151,7 +151,6 @@ class VersionCommand extends FlutterCommand {
         context: PubContext.pubUpgrade,
         directory: projectRoot,
         upgrade: true,
-        checkLastModified: false,
         generateSyntheticPackage: false,
       );
     }
diff --git a/packages/flutter_tools/lib/src/context_runner.dart b/packages/flutter_tools/lib/src/context_runner.dart
index 50d3dbe5b47..f79a1b0bdfe 100644
--- a/packages/flutter_tools/lib/src/context_runner.dart
+++ b/packages/flutter_tools/lib/src/context_runner.dart
@@ -236,8 +236,6 @@ Future<T> runInContext<T>(
         botDetector: globals.botDetector,
         platform: globals.platform,
         usage: globals.flutterUsage,
-        // Avoid a circular dependency by making this access lazy.
-        toolStampFile: () => globals.cache.getStampFileFor('flutter_tools'),
       ),
       ShutdownHooks: () => ShutdownHooks(logger: globals.logger),
       Stdio: () => Stdio(),
diff --git a/packages/flutter_tools/lib/src/dart/pub.dart b/packages/flutter_tools/lib/src/dart/pub.dart
index 9830ff414d5..b18e90887ff 100644
--- a/packages/flutter_tools/lib/src/dart/pub.dart
+++ b/packages/flutter_tools/lib/src/dart/pub.dart
@@ -80,7 +80,6 @@ abstract class Pub {
     @required Platform platform,
     @required BotDetector botDetector,
     @required Usage usage,
-    File Function() toolStampFile,
   }) = _DefaultPub;
 
   /// Runs `pub get`.
@@ -93,8 +92,6 @@ abstract class Pub {
     bool skipIfAbsent = false,
     bool upgrade = false,
     bool offline = false,
-    bool checkLastModified = true,
-    bool skipPubspecYamlCheck = false,
     bool generateSyntheticPackage = false,
     String flutterRootOverride,
   });
@@ -141,9 +138,7 @@ class _DefaultPub implements Pub {
     @required Platform platform,
     @required BotDetector botDetector,
     @required Usage usage,
-   File Function() toolStampFile,
-  }) : _toolStampFile = toolStampFile,
-       _fileSystem = fileSystem,
+  }) : _fileSystem = fileSystem,
        _logger = logger,
        _platform = platform,
        _botDetector = botDetector,
@@ -159,7 +154,6 @@ class _DefaultPub implements Pub {
   final Platform _platform;
   final BotDetector _botDetector;
   final Usage _usage;
-  final File Function() _toolStampFile;
 
   @override
   Future<void> get({
@@ -168,88 +162,52 @@ class _DefaultPub implements Pub {
     bool skipIfAbsent = false,
     bool upgrade = false,
     bool offline = false,
-    bool checkLastModified = true,
-    bool skipPubspecYamlCheck = false,
     bool generateSyntheticPackage = false,
     String flutterRootOverride,
   }) async {
     directory ??= _fileSystem.currentDirectory.path;
-
-    final File pubSpecYaml = _fileSystem.file(
-      _fileSystem.path.join(directory, 'pubspec.yaml'));
     final File packageConfigFile = _fileSystem.file(
       _fileSystem.path.join(directory, '.dart_tool', 'package_config.json'));
     final Directory generatedDirectory = _fileSystem.directory(
       _fileSystem.path.join(directory, '.dart_tool', 'flutter_gen'));
 
-    if (!skipPubspecYamlCheck && !pubSpecYaml.existsSync()) {
-      if (!skipIfAbsent) {
-        throwToolExit('$directory: no pubspec.yaml found');
-      }
-      return;
-    }
-
-    final DateTime originalPubspecYamlModificationTime = pubSpecYaml.lastModifiedSync();
-
-    if (!checkLastModified || _shouldRunPubGet(
-      pubSpecYaml: pubSpecYaml,
-      packageConfigFile: packageConfigFile,
-    )) {
-      final String command = upgrade ? 'upgrade' : 'get';
-      final Status status = _logger.startProgress(
-        'Running "flutter pub $command" in ${_fileSystem.path.basename(directory)}...',
-        timeout: const TimeoutConfiguration().slowOperation,
+    final String command = upgrade ? 'upgrade' : 'get';
+    final Status status = _logger.startProgress(
+      'Running "flutter pub $command" in ${_fileSystem.path.basename(directory)}...',
+      timeout: const TimeoutConfiguration().slowOperation,
+    );
+    final bool verbose = _logger.isVerbose;
+    final List<String> args = <String>[
+      if (verbose)
+        '--verbose'
+      else
+        '--verbosity=warning',
+      ...<String>[
+        command,
+        '--no-precompile',
+      ],
+      if (offline)
+        '--offline',
+    ];
+    try {
+      await batch(
+        args,
+        context: context,
+        directory: directory,
+        failureMessage: 'pub $command failed',
+        retry: true,
+        flutterRootOverride: flutterRootOverride,
       );
-      final bool verbose = _logger.isVerbose;
-      final List<String> args = <String>[
-        if (verbose)
-          '--verbose'
-        else
-          '--verbosity=warning',
-        ...<String>[
-          command,
-          '--no-precompile',
-        ],
-        if (offline)
-          '--offline',
-      ];
-      try {
-        await batch(
-          args,
-          context: context,
-          directory: directory,
-          failureMessage: 'pub $command failed',
-          retry: true,
-          flutterRootOverride: flutterRootOverride,
-        );
-        status.stop();
-      // The exception is rethrown, so don't catch only Exceptions.
-      } catch (exception) { // ignore: avoid_catches_without_on_clauses
-        status.cancel();
-        rethrow;
-      }
+      status.stop();
+    // The exception is rethrown, so don't catch only Exceptions.
+    } catch (exception) { // ignore: avoid_catches_without_on_clauses
+      status.cancel();
+      rethrow;
     }
 
     if (!packageConfigFile.existsSync()) {
       throwToolExit('$directory: pub did not create .dart_tools/package_config.json file.');
     }
-    if (pubSpecYaml.lastModifiedSync() != originalPubspecYamlModificationTime) {
-      throwToolExit(
-        '$directory: unexpected concurrent modification of '
-        'pubspec.yaml while running pub.');
-    }
-    // We don't check if dotPackages was actually modified, because as far as we can tell sometimes
-    // pub will decide it does not need to actually modify it.
-    final DateTime now = DateTime.now();
-    if (now.isBefore(originalPubspecYamlModificationTime)) {
-      _logger.printError(
-        'Warning: File "${_fileSystem.path.absolute(pubSpecYaml.path)}" was created in the future. '
-        'Optimizations that rely on comparing time stamps will be unreliable. Check your '
-        'system clock for accuracy.\n'
-        'The timestamp was: $originalPubspecYamlModificationTime\n'
-        'The time now is: $now'
-      );
-    }
     await _updatePackageConfig(
       packageConfigFile,
       generatedDirectory,
@@ -392,23 +350,6 @@ class _DefaultPub implements Pub {
     return <String>[sdkPath, ...arguments];
   }
 
-  bool _shouldRunPubGet({ @required File pubSpecYaml, @required File packageConfigFile }) {
-    if (!packageConfigFile.existsSync()) {
-      return true;
-    }
-    final DateTime dotPackagesLastModified = packageConfigFile.lastModifiedSync();
-    if (pubSpecYaml.lastModifiedSync().isAfter(dotPackagesLastModified)) {
-      return true;
-    }
-    final File toolStampFile = _toolStampFile != null ? _toolStampFile() : null;
-    if (toolStampFile != null &&
-        toolStampFile.existsSync() &&
-        toolStampFile.lastModifiedSync().isAfter(dotPackagesLastModified)) {
-      return true;
-    }
-    return false;
-  }
-
   // Returns the environment value that should be used when running pub.
   //
   // Includes any existing environment variable, if one exists.
diff --git a/packages/flutter_tools/lib/src/runner/flutter_command.dart b/packages/flutter_tools/lib/src/runner/flutter_command.dart
index 7003262c1cc..9b803646728 100644
--- a/packages/flutter_tools/lib/src/runner/flutter_command.dart
+++ b/packages/flutter_tools/lib/src/runner/flutter_command.dart
@@ -950,9 +950,9 @@ abstract class FlutterCommand extends Command<void> {
       // First always update universal artifacts, as some of these (e.g.
       // ios-deploy on macOS) are required to determine `requiredArtifacts`.
       await globals.cache.updateAll(<DevelopmentArtifact>{DevelopmentArtifact.universal});
-
       await globals.cache.updateAll(await requiredArtifacts);
     }
+    Cache.releaseLock();
 
     await validateCommand();
 
@@ -979,11 +979,7 @@ abstract class FlutterCommand extends Command<void> {
         context: PubContext.getVerifyContext(name),
         generateSyntheticPackage: project.manifest.generateSyntheticPackage,
       );
-      // All done updating dependencies. Release the cache lock.
-      Cache.releaseLock();
       await project.ensureReadyForPlatformSpecificTooling(checkProjects: true);
-    } else {
-      Cache.releaseLock();
     }
 
     setupApplicationPackages();
diff --git a/packages/flutter_tools/test/general.shard/cache_test.dart b/packages/flutter_tools/test/general.shard/cache_test.dart
index 0e2bca75c56..e12efc10773 100644
--- a/packages/flutter_tools/test/general.shard/cache_test.dart
+++ b/packages/flutter_tools/test/general.shard/cache_test.dart
@@ -743,9 +743,6 @@ void main() {
     verify(pub.get(
       context: PubContext.pubGet,
       directory: 'packages/flutter_tools',
-      generateSyntheticPackage: false,
-      skipPubspecYamlCheck: true,
-      checkLastModified: false,
     )).called(1);
   });
 }
diff --git a/packages/flutter_tools/test/general.shard/dart/pub_get_test.dart b/packages/flutter_tools/test/general.shard/dart/pub_get_test.dart
index 1b76f9d8e8e..6919771558c 100644
--- a/packages/flutter_tools/test/general.shard/dart/pub_get_test.dart
+++ b/packages/flutter_tools/test/general.shard/dart/pub_get_test.dart
@@ -49,7 +49,7 @@ void main() {
     FakeAsync().run((FakeAsync time) {
       expect(processMock.lastPubEnvironment, isNull);
       expect(logger.statusText, '');
-      pub.get(context: PubContext.flutterTests, checkLastModified: false).then((void value) {
+      pub.get(context: PubContext.flutterTests).then((void value) {
         error = 'test completed unexpectedly';
       }, onError: (dynamic thrownError) {
         error = 'test failed unexpectedly: $thrownError';
@@ -114,7 +114,7 @@ void main() {
       processManager: MockProcessManager(66, stderr: 'err1\nerr2\nerr3\n', stdout: 'out1\nout2\nout3\n'),
     );
     try {
-      await pub.get(context: PubContext.flutterTests, checkLastModified: false);
+      await pub.get(context: PubContext.flutterTests);
       throw AssertionError('pubGet did not fail');
     } on ToolExit catch (error) {
       expect(error.message, 'pub get failed (66; err3)');
@@ -149,7 +149,7 @@ void main() {
       MockDirectory.findCache = true;
       expect(processMock.lastPubEnvironment, isNull);
       expect(processMock.lastPubCache, isNull);
-      pub.get(context: PubContext.flutterTests, checkLastModified: false).then((void value) {
+      pub.get(context: PubContext.flutterTests).then((void value) {
         error = 'test completed unexpectedly';
       }, onError: (dynamic thrownError) {
         error = 'test failed unexpectedly: $thrownError';
@@ -182,7 +182,7 @@ void main() {
       expect(processMock.lastPubCache, isNull);
 
       String error;
-      pub.get(context: PubContext.flutterTests, checkLastModified: false).then((void value) {
+      pub.get(context: PubContext.flutterTests).then((void value) {
         error = 'test completed unexpectedly';
       }, onError: (dynamic thrownError) {
         error = 'test failed unexpectedly: $thrownError';
@@ -217,7 +217,6 @@ void main() {
     await pub.get(
       context: PubContext.flutterTests,
       generateSyntheticPackage: true,
-      checkLastModified: false,
     );
 
     verify(usage.sendEvent('pub-result', 'flutter-tests', label: 'success')).called(1);
@@ -255,7 +254,6 @@ void main() {
     await pub.get(
       context: PubContext.flutterTests,
       generateSyntheticPackage: true,
-      checkLastModified: false,
     );
 
     expect(
@@ -285,7 +283,7 @@ void main() {
       ),
     );
     try {
-      await pub.get(context: PubContext.flutterTests, checkLastModified: false);
+      await pub.get(context: PubContext.flutterTests);
     } on ToolExit {
       // Ignore.
     }
@@ -314,7 +312,7 @@ void main() {
     fileSystem.file('pubspec.yaml').writeAsStringSync('name: foo');
 
     try {
-      await pub.get(context: PubContext.flutterTests, checkLastModified: false);
+      await pub.get(context: PubContext.flutterTests);
     } on ToolExit {
       // Ignore.
     }
@@ -386,7 +384,7 @@ void main() {
     fileSystem.file('pubspec.yaml')
       ..createSync()
       ..setLastModifiedSync(DateTime(2001));
-    await pub.get(context: PubContext.flutterTests, checkLastModified: true); // pub sets date of .packages to 2002
+    await pub.get(context: PubContext.flutterTests); // pub sets date of .packages to 2002
 
     expect(logger.statusText, 'Running "flutter pub get" in /...\n');
     expect(logger.errorText, isEmpty);
@@ -398,44 +396,12 @@ void main() {
       .setLastModifiedSync(DateTime(2000));
     fileSystem.file('pubspec.yaml')
       .setLastModifiedSync(DateTime(2001));
-    await pub.get(context: PubContext.flutterTests, checkLastModified: true); // pub does nothing
+    await pub.get(context: PubContext.flutterTests); // pub does nothing
 
     expect(logger.statusText, 'Running "flutter pub get" in /...\n');
     expect(logger.errorText, isEmpty);
     expect(fileSystem.file('pubspec.yaml').lastModifiedSync(), DateTime(2001)); // because nothing should touch it
     logger.clear();
-
-    // bad scenario 2: pub changes pubspec.yaml instead
-    fileSystem.file('.dart_tool/package_config.json')
-      .setLastModifiedSync(DateTime(2000));
-    fileSystem.file('pubspec.yaml')
-      .setLastModifiedSync(DateTime(2001));
-    try {
-      await pub.get(context: PubContext.flutterTests, checkLastModified: true);
-      expect(true, isFalse, reason: 'pub.get did not throw');
-    } on ToolExit catch (error) {
-      expect(error.message, '/: unexpected concurrent modification of pubspec.yaml while running pub.');
-    }
-    expect(logger.statusText, 'Running "flutter pub get" in /...\n');
-    expect(logger.errorText, isEmpty);
-    expect(fileSystem.file('pubspec.yaml').lastModifiedSync(), DateTime(2002)); // because fake pub above touched it
-
-    // bad scenario 3: pubspec.yaml was created in the future
-    fileSystem.file('.dart_tool/package_config.json')
-      .setLastModifiedSync(DateTime(2000));
-    fileSystem.file('pubspec.yaml')
-      .setLastModifiedSync(DateTime(9999));
-    assert(DateTime(9999).isAfter(DateTime.now()));
-
-    await pub.get(context: PubContext.flutterTests, checkLastModified: true); // pub does nothing
-
-    expect(logger.statusText, contains('Running "flutter pub get" in /...\n'));
-    expect(logger.errorText, startsWith(
-      'Warning: File "/pubspec.yaml" was created in the future. Optimizations that rely on '
-      'comparing time stamps will be unreliable. Check your system clock for accuracy.\n'
-      'The timestamp was:'
-    ));
-    logger.clear();
   });
 }
 
diff --git a/packages/flutter_tools/test/integration.shard/downgrade_upgrade_integration_test.dart b/packages/flutter_tools/test/integration.shard/downgrade_upgrade_integration_test.dart
index 49180fc66aa..44c5b2ca0f7 100644
--- a/packages/flutter_tools/test/integration.shard/downgrade_upgrade_integration_test.dart
+++ b/packages/flutter_tools/test/integration.shard/downgrade_upgrade_integration_test.dart
@@ -24,7 +24,8 @@ final ProcessUtils processUtils = ProcessUtils(processManager: processManager, l
   outputPreferences: OutputPreferences.test(wrapText: true),
   timeoutConfiguration: const TimeoutConfiguration(),
 ));
-final String flutterBin = fileSystem.path.join(getFlutterRoot(), 'bin', 'flutter');
+final String flutterBin = fileSystem.path.join(getFlutterRoot(), 'bin', platform.isWindows ? 'flutter.bat' : 'flutter');
+final String dartBin = fileSystem.path.join(getFlutterRoot(), 'bin', platform.isWindows ? 'dart.bat' : 'dart');
 
 /// A test for flutter upgrade & downgrade that checks out a parallel flutter repo.
 void main() {