Issue “Module 'PDO' already loaded”

Describe the bug
When I run composer dump-auto it gives me an error:

Generating optimized autoload files
> Illuminate\Foundation\ComposerScripts::postAutoloadDump
> @php artisan package:discover --ansi
PHP Warning:  Module 'PDO' already loaded in Unknown on line 0

   ErrorException 

  session_start(): open(/opt/alt/php73/var/lib/php/session/sess_f0a04202322b17dfa4ad5af9cf1146e2, O_RDWR) failed: Read-only file system (30)

  at vendor/pragmarx/support/src/PhpSession.php:23
     19▕ 	private function startSession()
     20▕ 	{
     21▕ 		if ( ! $this->isStarted())
     22▕ 		{
  ➜  23▕ 			session_start();
     24▕ 		}
     25▕ 	}
     26▕ 
     27▕ 	private function isStarted()

      +36 vendor frames 
  37  [internal]:0
      Illuminate\Foundation\Application::Illuminate\Foundation\{closure}(Object(TCG\Voyager\VoyagerServiceProvider))

      +5 vendor frames 
  43  artisan:37
      Illuminate\Foundation\Console\Kernel::handle(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))

   Whoops\Exception\ErrorException 

  Module 'PDO' already loaded

  at Unknown:0
      1▕ 

      +1 vendor frames 
  2   [internal]:0
      Whoops\Run::handleShutdown()
Script @php artisan package:discover --ansi handling the post-autoload-dump event returned with error code 1

To Reproduce
Steps to reproduce the behavior:

1. Install a Laravel site;
2. Add pagkage tcg/voyager;
3. Add package pragmarx/tracker;
4. Add database connection tracker and run migrations;
5. Enable tracking via config/tracker.php file;
6. Run in terminal composer dump-autoload.

Expected behavior
To finish dump of autoload filewithout error.

Screenshots

System

• OS: Ubuntu 16.04
• Browser: Firefox
• Version: 84.0.2

Additional context
It is run on production server with shared hosting;

Start with the reported composer dump-autoload and php artisan package:discover output, then inspect config/tracker.php and the referenced vendor/pragmarx/support/src/PhpSession.php:23 call. Reproduce the package and database setup described on the shared-hosting environment; done means the autoload dump completes without the PDO or session errors.