CMake project with Unix Makefiles don't show source code

When loading a new cmake project with Qt Creator 4.1.0 cmake runs correctly and the project builds successfully. However, none of the source files show up in the Project pane and there does not appear to be any way to get them to show up.

The problem occurs with when using a CMake Generator for Unix Makefiles with CMake 2.8.7 or 3.5.2.

This used to work with Qt Creator 3.2.2 or 3.6.0. It also works if you use a different CMake Generator such as CodeBlocks Ninja.

Tested with a trivial project which is attached.