QtCreator cannot resolve any #includes in a CMake project

When I open a CMake C++ project, QtCreator cannot resolve any header includes, including the standard C and C++ headers. Basically, this makes QtCreator a simple text editor - no context-specific code highlighting, no navigation, no symbol resolution, etc. In Tools -> C++ -> Inspect C++ Code Model, on the Project Parts tab, everything is empty - no project parts, and no entries in the Defines and Header Paths tabs.

This is a regression since QtCreator 4.14.1, which opens the same project normally.

I cannot share this project as it is not public.