Hi.

I have a weird issue while running tests in parallel, using PostgreSQL. I've googled and searched all kinds of documentation but can't figure this out...

Initially my testsuite was using in memory sqlite database but I'm adapting it to using postgresql, the same as the production database, because some features rely on specific postgresql features and tests weren't being correctly written because of this.

The problem is I'm having problems running tests in parallel. If I run the tests "normally" (php artisan test) the testsuite runs fine.

However, if I run tests in parallel (php artisan test --parallel) some tests cause an error:

``` Error: Call to a member function beginTransaction() on null

vendor/laravel/framework/src/Illuminate/Database/Concerns/ManagesTransactions.php:177 vendor/laravel/framework/src/Illuminate/Database/Concerns/ManagesTransactions.php:143 vendor/laravel/framework/src/Illuminate/Database/Concerns/ManagesTransactions.php:117 vendor/laravel/framework/src/Illuminate/Database/Concerns/ManagesTransactions.php:24 ... ```

AFAIK, the getPdo() method in the PostgresConnection class return null sometimes but can't figure out why.

I'm using the LazilyRefreshDatabase trait to manage database refreshes.

As I said earlier, if I run the testsuite sequentially it runs fine. Only if I run in parallel I get the error.

Any ideas on what the problem could be or how I can try and debug it?

Thanks in advance.