完整错误
/Users/default/Library/Developer/Xcode/DerivedData/CloudClassRoom-cljzytkbllaohocmmuslpfdawime/Build/Products/Debug-iphonesimulator/DXPopover.bundle: bundle format unrecognized, invalid, or unsuitable
Command /usr/bin/codesign failed with exit code 1
从SVN上拉下来的项目，或者是自己下载的项目运行后提示上述错误的时候需要进行的操作
再重新运行即可。