xcode10 Command PhaseScriptExecution failed with a nonzero exit code

Command PhaseScriptExecution failed with a nonzero exit code

解决方法：

第一种：xcode菜单file->Workspace Settings->Build System 选择Legacy Build System 使用旧的编译系统即可。

第二种：sudo gem install cocoapods --pre

                 pod update                 

升级cocoapods到1.6.0beta，参考：cocoapods - Xcode 10 Command PhaseScriptExecution failed with a nonzero exit code (EXPANDED_CODE_SIGN_IDENTITY: unbound variable) - Stack Overflow