I download the newest Xcode from Apple, but I found I cannot search the library named \"libstdc++6.0.9\".
I was able to fix the build issue by copying the necessary files from 9.4 to 10.1, both platform libs and runtime. But it only resolves the cases with simulator. My app still stucks at start (splash screen) when running on physical device.
Copy it from old Xcode(9.4) will work for physical iOS devices.
For Simulator issues with Did find: /usr/lib/libstdc++.6.dylib: mach-o, but not built for iOS simulator
. Looks like apple removed compatibility support for simulator. Just download iOS 11.4 simulator and it can be run on it.