anchor.diff:        List<String> sharedOptions,
         List<String> originalArguments,
         CommandArtifact artifact) {
  -    return <String>[artifact.filename];
  +    final String suffix = isPrecompiler ? "/out.aotsnapshot" : "";
  +    return <String>["${artifact.filename}${suffix}"];
     }
   
     static ComposedCompilerConfiguration createDartKPConfiguration(
  
positive.code: 
  class ComposedCompilerConfiguration extends CompilerConfiguration {
    final List<PipelineCommand> pipelineCommands;
  
    ComposedCompilerConfiguration(this.pipelineCommands)
        : super._subclass();
  
    CommandArtifact computeCompilationArtifact(
  
negative.code:         new PrecompilerCompilerConfiguration(
            arch: arch, useBlobs: useBlobs, isAndroid: isAndroid)));
  
      return new ComposedCompilerConfiguration(nested, isPrecompiler: true);
    }
  
    static ComposedCompilerConfiguration createDartKConfiguration(
  