Swift Framework: Umbrella header '[...].h' not found

Question

In a custom framework containing both Objective-C and Swift code, the Swift compiler throws the following error:

[build_path]/unextended-module.modulemap:2:19: error: umbrella header 'bugtest.h' not found
  umbrella header "bugtest.h"
                  ^
<unknown>:0: error: could not build Objective-C module 'bugtest'

Answer 1

This usually happens after a project rename or something like that. The problem is that the umbrella header is no longer listed as a Public header. Check the attached image to see how to fix this.