?
万恶的[BEROR]error: There is no SDK with the name or path ‘iphoneos错误
相信所有的iOS都碰到过下载了别人的代码，由于sdk版本不同，代码不能编译。
很多人都知道应该去改Base SDK，顺利的话这一步就可以了。
当然如果碰到xcode的bug，这个时候你不得不来回切换debug和release模式，等能选device和similator才行。
如果不幸，你碰到了：
Build HeaderFooterX of project HeaderFooter with configuration Release
Check dependencies
[BEROR]error: There is no SDK with the name or path ‘iphoneos4.0′
恭喜你，你中奖了，这个破问题困扰了很多人，不过总算在茫茫互联网大海中我找到了正解:
had to not only change the Base SDK under Project – Edit Project Settings but I also had to change it under Project – Edit Active Target. Then in Overview drop down I had to click on Release, then back to Debug to update the menu and find Simulator 4.2.
对了，这样做才能彻底解决这个问题，keep moving on.