I download the newest Xcode from Apple, but I found I cannot search the library named \"libstdc++6.0.9\".
I've faced the same issue after updating to xcode 10. I've resolved this issue by downloading libstdc++.6.0.9.tbd and libstdc++.6.tbd from https://github.com/Kila2/libstdc-.6.0.9.tbd.
then i copied these files to my project folder. After that I added these libs in Linked Frameworks and Libraries by following these steps: Project > Target > General > Linked Frameworks and Libraries click (+) > Click 'Add Other' > Navigat to your project folder in 'Open File' and select these libraries and add.
Now run the project it will run perfectly..