Fix bots, address duplicate error reporting later.

pkg/front_end/lib/src/kernel_generator_impl.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// Defines the front-end API for converting source code to Dart Kernel objects.
 library front_end.kernel_generator_impl;
 
 import 'dart:async' show Future;
 import 'dart:async';
 
@@ skipping 116 matching lines @@
             dillTarget.loader.libraries.map((lib) => lib.importUri).toSet();
         trimProgram(program, (uri) => !excluded.contains(uri));
       }
       if (options.debugDump) {
         printProgramText(program, libraryFilter: kernelTarget.isSourceLibrary);
       }
       options.ticker.logMs("Generated program");
     }
 
     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;
     }
 
     return new CompilerResult(
         summary: summary,
         program: program,
         deps: kernelTarget.loader.getDependencies());
   } on deprecated_InputError catch (e) {
     options.report(
         deprecated_InputError.toMessage(e), Severity.internalProblem);
@@ skipping 12 matching lines @@
   final Program program;
 
   /// Dependencies traversed by the compiler. Used only for generating
   /// dependency .GN files in the dart-sdk build system.
   /// Note this might be removed when we switch to compute depencencies without
   /// using the compiler itself.
   final List<Uri> deps;
 
   CompilerResult({this.summary, this.program, this.deps});
 }