Error:Timeout waiting to lock proj class cache for build file '/Users/Jaycee/AndroidStudioProjects/H

项目打包时出现的错误：

Error:Timeout waiting to lock proj class cache for build file '/Users/Jaycee/AndroidStudioProjects/HJB/app/build.gradle' (/Users/Jaycee/.gradle/caches/2.8/scripts/build_2sbty0nj6yn7jxu8mpu70aw4o/proj). It is currently in use by another Gradle instance.

Owner PID: unknown
Our PID: 1120
Owner Operation: unknown
Our operation: Initialize cache

Lock file: /Users/Jaycee/.gradle/caches/2.8/scripts/build_2sbty0nj6yn7jxu8mpu70aw4o/proj/cache.properties.lock

直接找到/Users/Jaycee/.gradle/caches/2.8/scripts/该路径下的文件删除，重新同步，再打包运行。