I\'m testing React Native 0.56.0-rc.2 on Mac OS Mojave and Xcode 10.
Running:
react-native init TestProject --version=\"0.56.0-rc.2\"
cd TestProject
npm
A simple and quick resolution. In Xcode, go to File->Project/Workspace settings. Change the build system to Legacy Build system.
This is the resolution from Wesley's link. Saw something the other day about posting the direct answer and trying to avoid linking because links / websites can change. I was going to leave this as a comment, but don't have enough rep.