Cracks around one spoke may or may not mean much. But keep a close eye on the wheel from that point.

Two spokes I begin to worry more especially if they are adjacent spokes. Replace or ride becomes a judgement call but certainly no smash and bash stuff.

Three or more spokes with even small cracks tells me that the rim is on its last legs and I would not ride it anymore.

The need for frequent adjustments at that point means that the spokes are pulling through the rim at multiple points and failure is not far away. I certainly would not ride on any wheel that required the need to carry a spoke wrench so I could tune out brake pad scuffing over the duration of a single ride. That's just too scarey.