The codesign tool requires there only be one.问题解决办法

参考 ： Quick Fix: Open up KEYCHAIN ACCESS > click on MY CERTIFICATES> in there you will probably see iPhone Developer: . You will probably see it TWICE! Select the one with the earliest Expiration date, right click and select DELETE. Restart Xcode if you havent. Works now. :)   译文： 最简单的办法，点击“钥匙链访问”->查看“我的证书”，看其中是否存在同名的证书，删除过期的，再重启XCode,幸运的话，就可以解决这个问题。