I am getting the following error when building in Xcode 10.0 with swift 4.2:
I got this issue after resolving the conflicts in project.pbxproj.
Step 1: Removing the "Build input files cannot be found" files from BuildPhases -> Copy Bundle resources and adding them back worked for me.
If the above Step 1 doesn't work, search for "Recovered References" folder in your project structure and remove the files that are causing this issue and repeat Step 1.