因为要编译php的memcached扩展，所以需要这个库。为了省事，我使用的是brew自动安装
brew install libmemcached
安装到一半，提示错误
checking for libevent directory... configure: error: libevent is required. You can get it from http://www.monkey.org/~provos/libevent/
If it's already installed, specify its path using --with-libevent=/dir/但是libevent是安装过的，使用命令
brew install libevent
显示
Warning: It appears you have Macports or Fink installed Software installed with other package managers causes known problems for Homebrew. If formula fail to build uninstall Macports/Fink and reinstall any affected formula. Warning: Formula already installed: libevent
这又是怎么回事呢？难道非要我去下载源代码编译吗？
她的意思是你已经安装过macport，这个东西会和brew冲突，所以建议你使用port安装或者写在macport以后在尝试
如果真的想了解，源代码安装也不是很难的事情。