[monorepo, CMake] LLVM_ENABLE_PROJECTS question

I tried passing


to cmake and got this reported from cmake:

  llvm project is disabled

However, llvm does actually appear to be built. I don't recall seeing
this warning prior to using the monorepo but I can't be sure.

If I add llvm to the project list, it becomes:

  llvm project is enabled

It seems the disabled message is innocuous but I wonder if there is
something more going on. Does "enabling" the LLVM project cause the
build to behave differently in some way?