diff --git a/bin/cache/dart-sdk.version b/bin/cache/dart-sdk.version
index ae09bbd17e6..41e2496af1b 100644
--- a/bin/cache/dart-sdk.version
+++ b/bin/cache/dart-sdk.version
@@ -1 +1 @@
-1.20.0-dev.1.0
+1.20.0-dev.5.0
diff --git a/packages/flutter_test/lib/src/controller.dart b/packages/flutter_test/lib/src/controller.dart
index 0d985824a4c..47e09d18017 100644
--- a/packages/flutter_test/lib/src/controller.dart
+++ b/packages/flutter_test/lib/src/controller.dart
@@ -74,7 +74,7 @@ class WidgetController {
   /// * Use [firstWidget] if you expect to match several but only want the first.
   Iterable<Widget/*=T*/> widgetList/*<T extends Widget>*/(Finder finder) {
     TestAsyncUtils.guardSync();
-    return finder.evaluate().map((Element element) => element.widget);
+    return finder.evaluate().map/*<T>*/((Element element) => element.widget);
   }
 
 
@@ -219,7 +219,7 @@ class WidgetController {
   /// * Use [firstRenderObject] if you expect to match several but only want the first.
   Iterable<RenderObject/*=T*/> renderObjectList/*<T extends RenderObject>*/(Finder finder) {
     TestAsyncUtils.guardSync();
-    return finder.evaluate().map((Element element) => element.renderObject);
+    return finder.evaluate().map/*<T>*/((Element element) => element.renderObject);
   }
 
 
diff --git a/packages/flutter_tools/lib/executable.dart b/packages/flutter_tools/lib/executable.dart
index ddcd53f3a0b..e9148ac0ab1 100644
--- a/packages/flutter_tools/lib/executable.dart
+++ b/packages/flutter_tools/lib/executable.dart
@@ -85,7 +85,7 @@ Future<Null> main(List<String> args) async {
     ..addCommand(new UpdatePackagesCommand(hidden: !verboseHelp))
     ..addCommand(new UpgradeCommand());
 
-  return Chain.capture(() async {
+  return Chain.capture/*<Future<Null>>*/(() async {
     // Initialize globals.
     context[Logger] = new StdoutLogger();
     context[DeviceManager] = new DeviceManager();
diff --git a/packages/flutter_tools/lib/src/dart/analysis.dart b/packages/flutter_tools/lib/src/dart/analysis.dart
index 6af4473b9c5..6f27a02d73e 100644
--- a/packages/flutter_tools/lib/src/dart/analysis.dart
+++ b/packages/flutter_tools/lib/src/dart/analysis.dart
@@ -10,6 +10,7 @@ import 'package:analyzer/file_system/physical_file_system.dart';
 import 'package:analyzer/plugin/options.dart';
 import 'package:analyzer/source/analysis_options_provider.dart';
 import 'package:analyzer/source/error_processor.dart';
+import 'package:analyzer/source/package_map_resolver.dart';
 import 'package:analyzer/src/context/builder.dart'; // ignore: implementation_imports
 import 'package:analyzer/src/dart/sdk/sdk.dart'; // ignore: implementation_imports
 import 'package:analyzer/src/generated/engine.dart'; // ignore: implementation_imports
@@ -32,6 +33,8 @@ class AnalysisDriver {
   AnalysisOptionsProvider analysisOptionsProvider =
       new AnalysisOptionsProvider();
 
+  file_system.ResourceProvider resourceProvider = PhysicalResourceProvider.INSTANCE;
+
   AnalysisContext context;
 
   DriverOptions options;
@@ -110,7 +113,7 @@ class AnalysisDriver {
       resolvers.add(new DartUriResolver(sdk));
     } else {
       // Fall back to a standard SDK if no embedder is found.
-      FolderBasedDartSdk sdk = new FolderBasedDartSdk(PhysicalResourceProvider.INSTANCE,
+      FolderBasedDartSdk sdk = new FolderBasedDartSdk(resourceProvider,
           PhysicalResourceProvider.INSTANCE.getFolder(sdkDir));
       sdk.analysisOptions = context.analysisOptions;
 
@@ -118,11 +121,15 @@ class AnalysisDriver {
     }
 
     if (options.packageRootPath != null) {
-      JavaFile packageDirectory = new JavaFile(options.packageRootPath);
-      resolvers.add(new PackageUriResolver(<JavaFile>[packageDirectory]));
+      ContextBuilder builder = new ContextBuilder(resourceProvider, null, null);
+      builder.defaultPackagesDirectoryPath = options.packageRootPath;
+      PackageMapUriResolver packageUriResolver = new PackageMapUriResolver(resourceProvider,
+          builder.convertPackagesToMap(builder.createPackageMap('')));
+
+      resolvers.add(packageUriResolver);
     }
 
-    resolvers.add(new file_system.ResourceUriResolver(PhysicalResourceProvider.INSTANCE));
+    resolvers.add(new file_system.ResourceUriResolver(resourceProvider));
     return resolvers;
   }