copyToOutputPath(inputPath) {
    let outputPath = this.outputPath;

    fs.mkdirsSync(outputPath);

    if (!this.canDeleteOutputPath(outputPath)) {
      throw new SilentError(`Using a build destination path of \`${outputPath}\` is not supported.`);
    }

    let sync = this._sync;
    if (sync === undefined) {
      this._sync = sync = new Sync(inputPath, path.resolve(this.outputPath));
    }

    let changes = sync.sync();

    return changes.map((op) => op[1]);
  }
@private
@method copyToOutputPath
@param {String} inputPath