Fix bots, address duplicate error reporting later.

pkg/front_end/lib/src/kernel_generator_impl.dart

Index: pkg/front_end/lib/src/kernel_generator_impl.dart
diff --git a/pkg/front_end/lib/src/kernel_generator_impl.dart b/pkg/front_end/lib/src/kernel_generator_impl.dart
index 470dee0318d4dd7b16136fc552d4a4cebe40d0e5..8dd871af4bbda05d5e6ae60740b3f39ff1b49cd3 100644
--- a/pkg/front_end/lib/src/kernel_generator_impl.dart
+++ b/pkg/front_end/lib/src/kernel_generator_impl.dart
@@ -134,8 +134,10 @@ Future<CompilerResult> generateKernelInternal(
     }
 
     if (kernelTarget.errors.isNotEmpty) {
-      // Note: we don't report errors here because they have been already
-      // reported through the compiler context.
+      // TODO(sigmund): remove duplicate error reporting. Currently
+      // kernelTarget.errors contains recoverable and unrecoverable errors. We
+      // are reporting unrecoverable errors twice.
+      kernelTarget.errors.forEach((e) => options.report(e, Severity.error));
       return null;
     }