message: No preferred generator for Emscripten
diff: @@ -255,9 +255,6 @@ async function tryCreateEmscriptenEnvironment(emscripten: string): Promise<Envir
  'CMAKE_TOOLCHAIN_FILE': cmake_toolchain
  },
  variables: new Map<string, string>([]),
  - preferredGenerator: {
  - name: 'Ninja'
  - }
  };
  return ret;
  }
  @@ -327,9 +324,9 @@ const ENVIRONMENTS: EnvironmentProvider[] = [
  {
  async getEnvironments(): Promise<Environment[]> {
  var dirs = config.emscriptenSearchDirs;
  - var env_dir = process.env['EMSCRIPTEN'];
  + var env_dir = process.env['EMSCRIPTEN'] as string|undefined;
  if (env_dir && dirs.indexOf(env_dir) == -1)
  - dirs = dirs.concat(env_dir);
  + dirs = dirs.push(env_dir);
  const envs = await Promise.all(dirs.map(tryCreateEmscriptenEnvironment));
  return <Environment[]>envs.filter((e) => !!e);
  }
  