CMake caches variables and settings in the CMakeCache.txt file. When you load a project for the first time, this file is generated in the build directory (cmake-build-debug or cmake-build-release by default) according to the contents of CMakeLists.txt.
If required, you can open and edit CMakeCache.txt as a regular text file. For this, use the icon in the CMake Tool Window or locate the file in the project tree.
Reset CMake cache
To reset the CMake cache without affecting the CLion cache, do one of the following:
Click the icon in the CMake tool window and choose Reset Cache and Reload Project from the drop-down menu.
Call Reset Cache and Reload Project using the Find Action dialog (Ctrl+Shift+A).