Confusing default bootstrapping for "test" env

[phansys]

Given the changes made at #491, using config/bootstrap.php as bootstrap of phpunit is not possible if .env.local.php exists without variables that closely belongs to the "test" env ("KERNEL_CLASS", "SYMFONY_DEPRECATIONS_HELPER", etc); since the file from where these variables should be loaded (.env.test) isn't required at all:

recipes/symfony/phpunit-bridge/3.3/.env.test

Lines 2 to 4 in c466e7a

	KERNEL_CLASS='App\Kernel'
	APP_SECRET='s$cretf0rt3st'
	SYMFONY_DEPRECATIONS_HELPER=999999

Since these variables are not common for the local environment, the dumped array at .env.local.php doesn't contains them, making the test suite unusable without changes:

recipes/symfony/framework-bundle/3.3/config/bootstrap.php

Lines 9 to 13 in c466e7a

	if (is_array($env = @include dirname(__DIR__).'/.env.local.php')) {
	$_ENV += $env;
	} elseif (!class_exists(Dotenv::class)) {
	throw new RuntimeException('Please run "composer require symfony/dotenv" to load the ".env" files configuring the application.');
	} else {

[nicolas-grekas]

Yes, that's correct. We need to enhance documentation around this as it's quite new.
As you spotted, .env.local.php freezes .env files. As such and on purpose, it's only for prod-like needs. Don't use it in test nor dev.