Thank you Etresoft for taking the time to reply; at least it saves me time in terms of not trying to chase down a non-existent solution.

This was a very painful one to find so I'm going to write as much as I can here about how to fix it if you encounter the same. First, this will likely only apply to those using CMake for their builds. It comes down ultimately to the MACOSX_BUNDLE facility needing to be reading the right Info.plist and not default to its internal cmake one. If you don't specify an explicit Info.plist to use you'll likely run in to this drama. set_target_properties(project_name PROPERTIES MACOSX_BUNDLE TRUE MACOSX_BUNDLE_INFO_PLIST ${CMAKE_CURRENT_SOURCE_DIR}/Info.plist