there are two ionic items on hand. After updating Xcode10, one of them is free, and the other one reports an error, as shown in figure

then there is no other hint. I also checked the information on the Internet and felt that it was foggy. Later, I will delete some libraries to see whose problem it is, because there is a project that is also ionic, but there is no error

Edit:
found the solution to the problem. The initial problem is because the project plug-in uses the library of CPP. Before Xcode10, lstdcPP.6.0.9 is automatically referenced. After updating to Xcode10, this is discarded, so the solution is to delete the reference to lstdcPP.6.0.9