Para resolver el error de Build de iOS 11 una vez que hemos instalado la librería React Native Vector Icons, hay que eliminar las entradas duplicadas en Copy Bundle Resources desde Xcode : https://github.com/oblador/react-native-vector-icons/issues/1074
«So to fix the problem, just remove the font files from Copy Bundle Resources
, so that they are only in [CP] Copy Pods Resources
.»