CMake not generating CMakeFiles/Makefile.cmake

I’m using CMake (3.18.2) with CLion under Linux, and I’m hitting a weird problem with generating unix makefiles in my project. Specifically, CLion expects there to be a CMakeFiles/Makefile.cmake file that it uses for dependency information that isn’t getting created. I get the same results when running cmake from the command line.

Now, this doesn’t seem to affect the build–CLion just complains about it (and has some other odd behaviour that may or may not be related).

The project isn’t terribly complex: a few sub-projects that create libraries, a few custom targets for copying files, and a single executable. Running cmake on the subprojects works as expected; only generating the top level project with the executable has problems.

Any thoughts on what might be happening?

It sounds like generation fails. Are there any associated error messages available?