Mac 下出现Gradle sync failed: SDK location not found. Define location with sdk.dir in the local.properties
检查了下环境变量和local.properties 都已经设置了sdk路径，后来google了下发现Mac需要执行
launchctl setenv ANDROID_HOME /Users/xxx/Documents/ProgramFiles/adt-eclipse/sdk然后重新启动android studio，就好了