Circular Dependency Issue when Building Project

As a way of practicing using Geant4 and understanding how to build an executable using CMake, I’ve copied and changed some parts of example B1 (mostly the CMakeLists.txt file) to see if I can build my own project. I had no issues configuring the build directory but when I run

cmake --build . --config Release

I get the following error

I can’t figure out what the issue is. Any help would be much appreciated.