直接运行port提示：

Error: Current platform "darwin 14" does not match expected platform "darwin 13"
Error: If you upgraded your OS, please follow the migration instructions: https://trac.macports.org/wiki/Migration
OS platform mismatch
while executing
"mportinit ui_options global_options global_variations"
Error: /opt/local/bin/port: Failed to initialize MacPorts, OS platform mismatch

经查，由于Yosemite没有正式发布，故官方尚未提供Yosemite的二进制安装包，只需要下载MacPorts源码编译安装一次即可 ...