This started to happen on Codeship and local for me and other developers. Though one developer had a higher setting for max nesting as noted here I wanted to not worry about this so I just locked down Symfony and Behat in our composer.json file

	"require-dev": {
        "symfony/dependency-injection": "2.7.x-dev#9fcd589dfb67697f1e3e34611b97eb1be2cd85be",
        "php-vcr/php-vcr": "dev-master",
        "phpunit/phpunit": "~4.0",
        "phpspec/phpspec": "~2.1",
        "php-vcr/phpunit-testlistener-vcr": "dev-master",
        "mockery/mockery": "*@dev",
        "fzaninotto/faker": "*",
        "guzzlehttp/guzzle": "4.*",
        "pda/pheanstalk": "~3.0",
        "knplabs/github-api": "1.2.1",
        "way/generators": "~3.0",
        "symfony/Yaml":"2.1.x-dev",
        "behat/behat": "dev-master#ec1e3890d3753908695483ca1f3cf7304c02251f",
	 "behat/mink": "dev-master#30014f0a15579176b7fca879cb461aad900f4db5",
	 "behat/mink-extension": "dev-master#ba5329be65a816adfc2d9ba9b639a92f548371da",
	 "laracasts/behat-laravel-extension": "dev-master#205a3d217d33d4315d20d0f3497edd65a8b5443e"
	},

And then

rm -rf vendor composer.lock && composer install

And bin/behat -dl and other behat tests worked again