今天尝试着配置了一下 php 的运行环境，在安装 composer 后执行 composer install 时出现了如下错误：
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.
Problem 1
- Installation request for intervention/image 2.4.2 -> satisfiable by intervention/image[2.4.2].
- intervention/image 2.4.2 requires ext-fileinfo * -> the requested PHP extension fileinfo is missing from your system.
Problem 2
- Installation request for league/flysystem 1.0.49 -> satisfiable by league/flysystem[1.0.49].
- league/flysystem 1.0.49 requires ext-fileinfo * -> the requested PHP extension fileinfo is missing from your system.
Problem 3
- league/flysystem 1.0.49 requires ext-fileinfo * -> the requested PHP extension fileinfo is missing from your system.
- laravel/framework v5.5.44 requires league/flysystem ^1.0.8 -> satisfiable by league/flysystem[1.0.49].
- Installation request for laravel/framework v5.5.44 -> satisfiable by laravel/framework[v5.5.44].
To enable extensions, verify that they are enabled in your .ini files:
- C:\Program Files\PHP\v7.3\php.ini
You can also run `php --ini` inside terminal to see which files are used by PHP in CLI mode.经尝试，在 php.ini 中的 [ExtensionList] 加上 extension=php_fileinfo.dll 就可以正常运行了。