Swap isn't allocated at installation, it's done at pool creation. And your disk has a swap partition, but for some reason it isn't being used right now. I'd suggest submitting a bug report through the web GUI (using the support button), and checking the box to attach a debug file.
Many folks don't use swap (OTOH, even with 128 GB of RAM, I use a little bit of swap), but you should nonetheless have some allocated and available. You have the partition, but it doesn't seem to be active, and it should be.