The rules stipulate that if you can't See a Raise, you have to Give. But who Gives when you can See just fine, but then can't turn around and Raise?

Your only choices when it's your turn are Raise or Give. There's no passing. If you can't or won't Raise - for whatever reason, including you've got no dice - you have to Give.

The reason this isn't specifically spelled out in the text is that it's never happened in play in my experience. At that moment, a player can either improvise something from the locale and/or pull in a new trait and get the dice they need to raise.