我收到以下错误：
无法在 laravel 6.5.1 上制作“composer require laravel/ui --dev”。我收到错误消息“无法将您的要求解析为一组可安装的软件包。
问题1：
安装失败，将 ./composer.json 恢复为其原始内容。
在我的 composer.json
"name": "laravel/laravel",
"type": "project",
"description": "The Laravel Framework.",
"keywords": [
"framework",
"laravel"
],
"license": "MIT",
"require": {
"php": "^7.2",
"fideloper/proxy": "^4.0",
"laravel/framework": "^6.2",
"laravel/tinker": "^1.0",
"laravelcollective/html": "^5.2.0",
"tcg/voyager": "^1.3"
},
"require-dev": {
"facade/ignition": "^1.4",
"fzaninotto/faker": "^1.4",
"mockery/mockery": "^1.0",
"nunomaduro/collision": "^3.0",
"phpunit/phpunit": "^8.0"
},
"config": {
"optimize-autoloader": true,
"preferred-install": "dist",
"sort-packages": true
},
"extra": {
"laravel": {
"dont-discover": []
}
},
"autoload": { …