"the user operation is waiting for building workspace" to complete"，
解决办法：
1.选择菜单栏的“Project”,然后把菜单栏中“Build Automatically”前面的对钩去掉。
2.当你修改或添加代码后，选择菜单栏的“Project”,然后选择菜单栏中“Build All”就可以再次编译了。
eclipse the user operation is waiting for building workspace" to complete
原文：http://www.cnblogs.com/Sunnor/p/4699338.html