我使用 Composer 命令通过 CMD 从 7.x 更新我的 laravel 版本到 8.0，composer update但我收到错误
D:\xampp\htdocs\salebaba>composer update
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.
Problem 1
- Conclusion: don't install laravel/framework v8.5.0
- Conclusion: don't install laravel/framework v8.4.0
- Conclusion: don't install laravel/framework v8.3.0
- Conclusion: don't install laravel/framework v8.2.0
- Conclusion: don't install laravel/framework v8.1.0
- Conclusion: don't install laravel/framework v8.0.4
- Conclusion: don't install laravel/framework …