问题

今天升级了一下Xcode，发现Qt运行报错：No rule to make target `xxx'. Stop。
查看Qt编译输出为：

The platform SDK has been changed from version 10.14 to version 10.15.
This requires a fresh build. Please wipe the build directory completely,
including any .qmake.stash and .qmake.cache files generated by qmake.

解决

如上图，删除路径：用户名/.qmake.stash 文件，重新编译即可。还不行的话，点击Qt上边菜单：构建->执行qmake即可。