How to create a semaphore importable by cuImportExternalSemaphore?

How can I create a semaphore importable by cuImportExternalSemaphore (specifically on Windows)? Is creating a semaphore via Vulkan the only option (CreateSemaphore does not work for me)? Dragging in a complex (graphics!) dependency in seems like a pain, especially if I want to use the new cuMem-options for IPC on Windows (no graphics), or if I want to use OpenGL for graphics and not Vulkan.