cannot turn off cmake option if the option is broken

in cmake, when we create an option like so

option(ENABLE_EXPERIMENTAL_FEATURE "Enable experimental feature" OFF)

it creates a check box in the project settings.

And if we go into projects settings toggle that checkbox and click on 'Apply Configuration Changes' , but turns out that we made a silly mistake in our cmake (failing during the generation phase), we won't be able to un-toggle that checkbox.  Clicking on 'Apply Configuration Changes' does nothing. You will be literally stuck there. Closing and Reopening the project won't fix it. nuking the build location entirely won't fix it.

I finally discovered that closing QtCreator and then deleting CMakeLists.txt.user from the source folder, which is generated by QtCreator, is the only way to get us out of this predicament.