diff --git a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
index 74ab0a7d7c8..20b9e29b1dd 100644
--- a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
@@ -1106,8 +1106,9 @@ abstract class BodyBuilder extends ScopeListener<JumpTarget>
       expression.extend();
     } else {
       VariableDeclaration variable = new VariableDeclarationJudgment.forValue(
-          expression, functionNestingLevel);
-      push(new CascadeJudgment(variable));
+          expression, functionNestingLevel)
+        ..fileOffset = expression.fileOffset;
+      push(new CascadeJudgment(variable)..fileOffset = expression.fileOffset);
       push(new VariableUseGenerator(this, token, variable));
     }
   }
diff --git a/pkg/front_end/lib/src/fasta/kernel/verifier.dart b/pkg/front_end/lib/src/fasta/kernel/verifier.dart
index fc9e8176e8f..547e01f7e6a 100644
--- a/pkg/front_end/lib/src/fasta/kernel/verifier.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/verifier.dart
@@ -117,7 +117,12 @@ class FastaVerifyingVisitor extends VerifyingVisitor
   visitAsExpression(AsExpression node) {
     super.visitAsExpression(node);
     if (node.fileOffset == -1) {
-      problem(node, "No offset for $node");
+      TreeNode parent = node.parent;
+      while (parent != null) {
+        if (parent.fileOffset != -1) break;
+        parent = parent.parent;
+      }
+      problem(parent, "No offset for $node", context: node);
     }
   }
 
diff --git a/pkg/front_end/test/fasta/bootstrap_test.dart b/pkg/front_end/test/fasta/bootstrap_test.dart
index 752038c93c8..13ee2f34b20 100644
--- a/pkg/front_end/test/fasta/bootstrap_test.dart
+++ b/pkg/front_end/test/fasta/bootstrap_test.dart
@@ -46,18 +46,17 @@ Future main() async {
 
 Future runCompiler(Uri compiler, Uri input, Uri output) async {
   Uri dartVm = Uri.base.resolveUri(new Uri.file(Platform.resolvedExecutable));
-  StdioProcess result = await StdioProcess.run(dartVm.toFilePath(), <String>[
-    "-c",
-    "--no_preview_dart_2",
-    compiler.toFilePath(),
-    "--compile-sdk=sdk/",
-    "--output=${output.toFilePath()}",
-    "--verify",
-    input.toFilePath(),
-  ]);
-  if (result.output.isNotEmpty) {
-    print(result.output);
-  }
+  StdioProcess result = await StdioProcess.run(
+      dartVm.toFilePath(),
+      <String>[
+        compiler.toFilePath(),
+        "--compile-sdk=sdk/",
+        "--output=${output.toFilePath()}",
+        "--verify",
+        "--strong",
+        input.toFilePath(),
+      ],
+      suppressOutput: false);
   if (result.exitCode != 0) {
     throw "Compilation failed.";
   }
diff --git a/runtime/lib/convert_patch.dart b/runtime/lib/convert_patch.dart
index 34fa1e64720..6ba84444c78 100644
--- a/runtime/lib/convert_patch.dart
+++ b/runtime/lib/convert_patch.dart
@@ -1075,7 +1075,7 @@ abstract class _ChunkedJsonParser<T> {
    * This function scans through the string literal for escapes, and copies
    * slices of non-escape characters using [addSliceToString].
    */
-  int parseStringToBuffer(position) {
+  int parseStringToBuffer(int position) {
     int end = chunkEnd;
     int start = position;
     while (true) {