Program: 53500
Project: 53500
Buggy source:
private String compileToJs(CompilerOptions compilerOptions,File applicationDir,String moduleName,List<MockResource> applicationResources,MinimalRebuildCache minimalRebuildCache,Set<String> expectedProcessedStaleTypeNames,JsOutputOption output) throws IOException, UnableToCompleteException, InterruptedException {
  System.setProperty(UnitCacheSingleton.GWT_PERSISTENTUNITCACHE,"String_Node_Str");
  Thread.sleep(1001);
  PrintWriterTreeLogger logger=new PrintWriterTreeLogger();
  logger.setMaxDetail(TreeLogger.ERROR);
  File outputDir=new File(applicationDir.getPath() + File.separator + moduleName);
  if (outputDir.exists()) {
    Util.recursiveDelete(outputDir,true);
  }
  ResourceLoader resourceLoader=ResourceLoaders.forClassLoader(Thread.currentThread());
  resourceLoader=ResourceLoaders.forPathAndFallback(ImmutableList.of(applicationDir),resourceLoader);
  compilerOptions.setIncrementalCompileEnabled(true);
  compilerOptions.setWarDir(applicationDir);
  compilerOptions.setModuleNames(ImmutableList.of(moduleName));
  compilerOptions.setOutput(output);
  CompilerContext compilerContext=new CompilerContext.Builder().options(compilerOptions).minimalRebuildCache(minimalRebuildCache).build();
  for (  MockResource applicationResource : applicationResources) {
    writeResourceTo(applicationResource,applicationDir);
  }
  ModuleDefLoader.clearModuleCache();
  ModuleDefLoader.loadFromResources(logger,compilerContext,moduleName,resourceLoader,true);
  Compiler compiler=new Compiler(compilerOptions,minimalRebuildCache);
  compiler.run(logger);
  File outputJsFile=null;
  outputDir=new File(applicationDir.getPath() + File.separator + moduleName);
  if (outputDir.exists()) {
    for (    File outputFile : outputDir.listFiles()) {
      if (outputFile.getPath().endsWith("String_Node_Str")) {
        outputJsFile=outputFile;
        break;
      }
    }
  }
  assertNotNull(outputJsFile);
  assertEquals(expectedProcessedStaleTypeNames,minimalRebuildCache.getProcessedStaleTypeNames());
  return Files.toString(outputJsFile,Charsets.UTF_8);
}

Fixed version (ground truth):
private String compileToJs(CompilerOptions compilerOptions,File applicationDir,String moduleName,List<MockResource> applicationResources,MinimalRebuildCache minimalRebuildCache,Set<String> expectedProcessedStaleTypeNames,JsOutputOption output) throws IOException, UnableToCompleteException, InterruptedException {
  System.setProperty(UnitCacheSingleton.GWT_PERSISTENTUNITCACHE,"String_Node_Str");
  Thread.sleep(1001);
  PrintWriterTreeLogger logger=new PrintWriterTreeLogger();
  logger.setMaxDetail(TreeLogger.ERROR);
  File outputDir=new File(applicationDir.getPath() + File.separator + moduleName);
  if (outputDir.exists()) {
    Util.recursiveDelete(outputDir,true);
  }
  ResourceLoader resourceLoader=ResourceLoaders.forClassLoader(Thread.currentThread());
  resourceLoader=ResourceLoaders.forPathAndFallback(ImmutableList.of(applicationDir),resourceLoader);
  compilerOptions.setIncrementalCompileEnabled(true);
  compilerOptions.setWarDir(applicationDir);
  compilerOptions.setModuleNames(ImmutableList.of(moduleName));
  compilerOptions.setOutput(output);
  CompilerContext compilerContext=new CompilerContext.Builder().options(compilerOptions).minimalRebuildCache(minimalRebuildCache).build();
  for (  MockResource applicationResource : applicationResources) {
    writeResourceTo(applicationResource,applicationDir);
  }
  ModuleDefLoader.clearModuleCache();
  ModuleDefLoader.loadFromResources(logger,compilerContext,moduleName,resourceLoader,true);
  Compiler compiler=new Compiler(compilerOptions,minimalRebuildCache);
  compiler.run(logger);
  File outputJsFile=null;
  outputDir=new File(applicationDir.getPath() + File.separator + moduleName);
  if (outputDir.exists()) {
    for (    File outputFile : outputDir.listFiles()) {
      if (outputFile.getPath().endsWith("String_Node_Str")) {
        outputJsFile=outputFile;
        break;
      }
    }
  }
  assertNotNull(outputJsFile);
  if (expectedProcessedStaleTypeNames != null) {
    assertEquals(expectedProcessedStaleTypeNames,minimalRebuildCache.getProcessedStaleTypeNames());
  }
  return Files.toString(outputJsFile,Charsets.UTF_8);
}