Laravel6安装完报错

Laravel6安装完碰到如下报错

Symfony\Component\Debug\Exception\FatalErrorException
Declaration of Symfony\Component\Translation\TranslatorInterface::setLocale($locale) must be 
compatible with Symfony\Contracts\Translation\LocaleAwareInterface::setLocale(string $locale)

解决方案，在composer.json里面加入

"symfony/translation-contracts": "^1.1.6"

    "require": {
        "php": "^7.2",
        "fideloper/proxy": "^4.0",
        "laravel/framework": "^6.2",
        "laravel/tinker": "^1.0",
    },

    "require": {
        "php": "^7.2",
        "fideloper/proxy": "^4.0",
        "laravel/framework": "^6.2",
        "laravel/tinker": "^1.0",
        "symfony/translation-contracts": "^1.1.6",
    },

之后执行命令

composer update
composer dump-autoload