I was running into a React Native build issue where I was getting this (only captured part of the error message, unfortunately):
Target Support Files/yoga/yoga.xcconfig: unable to open file (in target "yoga" in project "Pods") (in target 'yoga' from project 'Pods')
To fix:
rm -rf ios/build
rm -rf ios/Pods ios/Podfile.lock
cd ios; pod install; cd -
# restart packager
react-native run-ios
Picked this up debugging an issue, finally figured out that people may have to remove these from git and then push again as yoga has changed to "Yoga"