ThinkPHP 5.0 安装vendor 失败原因

当前环境

出错信息

In RootPackageLoader.php line 152:
                                                                            
  [RuntimeException]                                                        
  Root package 'topthink/think' cannot require itself in its composer.json  
  Did you accidentally name your root package after an external package?    
                                                                            

Exception trace:
  at phar://D:/phpstudy_pro/Extensions/composer1.8.5/composer.phar/src/Composer/Package/Loader/RootPackageLoader.php:152
 Composer\Package\Loader\RootPackageLoader->load() at phar://D:/phpstudy_pro/Extensions/composer1.8.5/composer.phar/src/Composer/Factory.php:381
 Composer\Factory->createComposer() at phar://D:/phpstudy_pro/Extensions/composer1.8.5/composer.phar/src/Composer/Factory.php:630
 Composer\Factory::create() at phar://D:/phpstudy_pro/Extensions/composer1.8.5/composer.phar/src/Composer/Console/Application.php:470
 Composer\Console\Application->getComposer() at phar://D:/phpstudy_pro/Extensions/composer1.8.5/composer.phar/src/Composer/Console/Application.php:594
 Composer\Console\Application->getPluginCommands() at phar://D:/phpstudy_pro/Extensions/composer1.8.5/composer.phar/src/Composer/Console/Application.php:212
 Composer\Console\Application->doRun() at phar://D:/phpstudy_pro/Extensions/composer1.8.5/composer.phar/vendor/symfony/console/Application.php:171
 Symfony\Component\Console\Application->run() at phar://D:/phpstudy_pro/Extensions/composer1.8.5/composer.phar/src/Composer/Console/Application.php:130
 Composer\Console\Application->run() at phar://D:/phpstudy_pro/Extensions/composer1.8.5/composer.phar/bin/composer:88
 require() at D:\phpstudy_pro\Extensions\composer1.8.5\composer.phar:29