You can also run `php --ini` inside terminal to see which files are used by PHP in CLI mode怎么解决
Laravel 项目安装验证码 mews/captcha 扩展，出现如下错误信息：
composer require mews/captcha
Using version ^2.2 for mews/captcha
./composer.json has been updated
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
- mews/captcha 2.2.0 requires intervention/image ~2.2 -> satisfiable by intervention/image[2.2.0, 2.2.1, 2.2.2, 2.3.0, 2.3.1, 2.3.10, 2.3.11, 2.3.12, 2.3.13, 2.3.14, 2.3.2, 2.3.3, 2.3.4, 2.3.5, 2.3.6
, 2.3.7, 2.3.8, 2.3.9, 2.4.0, 2.4.1, 2.4.2, 2.4.x-dev].
..........
- intervention/image 2.2.1 requires ext-fileinfo * -> the requested PHP extension fileinfo is missing from your system.
- intervention/image 2.2.0 requires ext-fileinfo * -> the requested PHP extension fileinfo is missing from your system.
- Installation request for mews/captcha ^2.2 -> satisfiable by mews/captcha[2.2.0, 2.2.1, 2.2.2, 2.2.3, 2.2.4].
To enable extensions, verify that they are enabled in your .ini files:
- D:\phpStudy\PHPTutorial\php\php-7.2.1-nts\php.ini
You can also run `php --ini` inside terminal to see which files are used by PHP in CLI mode.
Installation failed, reverting ./composer.json to its original content.
排查原因是php需要开启fileinfo扩展，
编辑php.ini文件，打开extension=php_fileinfo.dll 就可以了，重新运行composer命令，安装成功
composer require mews/captcha
Using version ^2.2 for mews/captcha
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 2 installs, 0 updates, 0 removals
- Installing intervention/image (2.4.2): Downloading (100%)
- Installing mews/captcha (2.2.4): Downloading (100%)
intervention/image suggests installing ext-imagick (to use Imagick based image processing.)
intervention/image suggests installing intervention/imagecache (Caching extension for the Intervention Image library)
Writing lock file
Generating optimized autoload files
> Illuminate\Foundation\ComposerScripts::postAutoloadDump
> @php artisan package:discover --ansi
Discovered Package: beyondcode/laravel-dump-server
Discovered Package: fideloper/proxy
Discovered Package: intervention/image
Discovered Package: laravel/nexmo-notification-channel
Discovered Package: laravel/slack-notification-channel
Discovered Package: laravel/tinker
Discovered Package: mews/captcha
Discovered Package: nesbot/carbon
Discovered Package: nunomaduro/collision
Package manifest generated successfully.
