我刚刚从几个月前拿了一个在拉拉维尔制作的项目。该项目还利用了Laravel Voyager-管理面板包。
浏览到 http://example.com/admin 后，我突然出现了这个奇怪的错误，我也不确定如何调试它。它看起来像这样：
Fatal error: Cannot declare class SymfonyComponentHttpFoundationAcceptHeader, because the name is already in use in /c/Users/User/Code/example-website/vendor/symfony/http-foundation/AcceptHeader.php on line 22
Fatal error: Uncaught Error: Class 'SymfonyComponentHttpFoundationAcceptHeaderItem' not found in /c/Users/User/Code/example-website/vendor/symfony/http-foundation/AcceptHeader.php:61 Stack trace: #0 [internal function]: SymfonyComponentHttpFoundationAcceptHeader::SymfonyComponentHttpFoundation{closure}(Array) #1 /c/Users/User/Code/example-website/vendor/symfony/http-foundation/AcceptHeader.php(57): array_map(Object(Closure), Array) #2 /c/Users/User/Code/example-website/vendor/symfony/http-foundation/Request.php(1664): SymfonyComponentHttpFoundationAcceptHeader::fromString('text/html,appli...') #3 /c/Users/User/Code/example-website/vendor/laravel/framework/src/Illuminate/Http/Concerns/InteractsWithContentTypes.php(54): SymfonyComponentHttpFoundationRequest->getAcceptableContentTypes() #4 /c/Users/User/Code/example-website/vendor/laravel/framework/src/Illuminate/Http/Concerns/InteractsWithContentTypes.php(44): IlluminateHttpRequest->wantsJson() #5 /c/Users/User/Code/example-website/vendor/laravel/framework/src/Illumina in /c/Users/User/Code/example-website/vendor/symfony/http-foundation/AcceptHeader.php on line 61
这个错误是非常意料之中的，我以前从未在我的项目（或其他任何地方）中看到过它。
如何调试此问题？
作为健全性检查，请删除vendor目录，然后运行composer install以重新获取依赖项并查看错误是否已解决。如果没有，则尝试composer update获取可能已解决此问题的依赖项的最新版本。