在PHP项目中Composer安装和加载第三方类库是很方便的方式，但是有时也难免出现一些错误令我们措手不及。
最近在一个项目中当我准备通过composer require安装一个微信的三方类库时，控制台报错：
Your requirements could not be resolved to an installable set of packages.
Problem 1
- topthink/think-installer v2.0.0 requires composer-plugin-api ^1.0 -> found composer-plugin-api[2.1.0] but it does not match the constraint.
- topthink/framework v5.1.41 requires topthink/think-installer 2.* -> satisfiable by topthink/think-installer[v2.0.0].
- topthink/framework is locked to version v5.1.41 and an update of this package was not requested.Installation failed, reverting ./composer.json and ./composer.lock to their original content.
看了composer.lock文件，然后尝试把版本号修改为报错提示的版本号，没想到竟然不行。哈哈哈哈~
解决办法一共有两个，第一种办法就是解决依赖版本的冲突。我们可以通过执行以下命令：
- composer require composer-plugin-api:1.0
第二种办法就是通过忽略依赖进行安装。
- composer require zoujingli/wechat-developer --ignore-platform-reqs
看到如下截图，问题得以解决。
