Error: Function name must be a string

[RikudouSage]

Here is the output of ./dilemma play -vvv

 Error

  Function name must be a string

  at app/Commands/PlayDilemmaGameCommand.php:56
    52|         ];
    53|
    54|         $cp = new ConsolePainter();
    55|         $warning = $cp->onRed()->bold()->yellow();
  > 56|         $this->line($warning('                                                  '));
    57|         $this->line($warning('   You and your partner have been arrested!       '));
    58|         $this->line($warning('                                                  '));
    59|         $this->line('');
    60|

  1   vendor/illuminate/container/BoundMethod.php:33
      App\Commands\PlayDilemmaGameCommand::handle()

  2   vendor/illuminate/container/BoundMethod.php:33
      call_user_func_array()

  3   vendor/illuminate/container/Util.php:37
      Illuminate\Container\BoundMethod::Illuminate\Container\{closure}()

  4   vendor/illuminate/container/BoundMethod.php:91
      Illuminate\Container\Util::unwrapIfClosure()

  5   vendor/illuminate/container/BoundMethod.php:35
      Illuminate\Container\BoundMethod::callBoundMethod()

  6   vendor/illuminate/container/Container.php:592
      Illuminate\Container\BoundMethod::call()

  7   vendor/illuminate/console/Command.php:134
      Illuminate\Container\Container::call()

  8   vendor/symfony/console/Command/Command.php:258
      Illuminate\Console\Command::execute()

  9   vendor/illuminate/console/Command.php:121
      Symfony\Component\Console\Command\Command::run()

  10  vendor/symfony/console/Application.php:911
      Illuminate\Console\Command::run()

  11  vendor/symfony/console/Application.php:264
      Symfony\Component\Console\Application::doRunCommand()

  12  vendor/symfony/console/Application.php:140
      Symfony\Component\Console\Application::doRun()

  13  vendor/illuminate/console/Application.php:93
      Symfony\Component\Console\Application::run()

  14  vendor/laravel-zero/foundation/src/Illuminate/Foundation/Console/Kernel.php:129
      Illuminate\Console\Application::run()

  15  vendor/laravel-zero/framework/src/Kernel.php:91
      Illuminate\Foundation\Console\Kernel::handle()

  16  dilemma:37
      LaravelZero\Framework\Kernel::handle()