This one fixes the build (public_header_files: The pattern includes header files that are not listedin source_files) and (module.modulemap:13:10: error: header 'DDContextFilterLogFormatter.h' not found).

But there might be a problem: the modulemap was excluding some files. Now, if we leave this to CocoaPods, all the headers will be public.

CocoaLumberjack.podspec

@@ -22,10 +22,7 @@ Pod::Spec.new do |s|
   s.osx.deployment_target = '10.7'
   s.watchos.deployment_target = '2.0'
   s.tvos.deployment_target = '9.0'
-  
-  s.public_header_files = 'Classes/*.h'
-  
-  s.module_map = 'Framework/Lumberjack/CocoaLumberjack.modulemap'
+
   s.default_subspecs = 'Default', 'Extensions'
 
   s.subspec 'Default' do |ss|