Lexical or preprocessor issue in react native while building ios app <React/RCTUtils.h> not found

Question

When I am trying to build my ios app in xcode, the build is failing due to lexical or preprocessor issue the error shows up like this

Answer 1

This was a problem specific to the react-native-device-info module.

For your specific case you may try v1.6.1 or higher (currently at 2.0 as of May 21, 2019) of the library and that should fix things for you.

For others interested more generally in the problem, this is a react-native library that uses native code, so it has an XCode project embedded within it for use in react-native after you run react-native link react-native-device-info. Unfortunately, the library was not including any directories in it's header search path, so it was of course unable to find the header files for the react-native objects it was using locally.

A library user proposed a change that fixed that problem for tvOS, and I extended the change to cover iOS as well, and now the library no longer generates errors like this for iOS or tvOS targets.

Perhaps someone with a similar issue may find the specific changes required for the fix useful in their projects