Solution: Copy -lstdc++.6.0.9and libstdc++wait for the library in Xcode9 to Xcode10 (both real machine and simulator need to be copied)
Enter the command in the terminal, open the lib library directory of Xcode , and copy the required library files from the Xcode9 directory to the Xcode10 directory: The
open command is as follows:
1) Real machine: open /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/lib
2) Simulator:open /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/usr/lib