Build failure on react-native init app

[yuanagain]

Hi, forgive my inexperience working with iOS. Following the instructions in the README (a few times now, by my count and as a check against human error), I am unable to build successfully.

My versions for React Native are as follows:
react-native-cli: 2.0.1
react-native: 0.59.5

Code from my sample project is here: https://github.com/tryboppity/react-native-share-extension-boilerplate

The only modifications I've made have been those prescribed in the README of this guide plus tweaking the build scheme. Prior to the latter, builds fail and I get error messages in XCode:

After adding React to the top of the scheme and unchecking the "parallelize" option, the warnings above go away, but I am still unable to build, getting this slew of errors:

Are the instruction in this README out of date? Is there something simple I'm missing?

Thanks!

[yuanagain]

Fixed via facebook/react-native#23183