Blue Marble Ice Cream already has a trike at Brooklyn Flea, and now they’re building a second one to debut on Governors Island this weekend or next. Owner Jennie Dundas tells us it will offer four or five flavors (including a sorbet) made by Hudson Valley dairy farmer Matt White. They’ll be sold in cups and cones for $3 and $4. Eventually, when the Water Taxi Beach adds its outdoor-indoor café in a few weeks, they’ll be served there too. In case of a delay, the shop has something else for you to do on Sunday — they’re bringing over a crew of Rwandan drummers for a concert and ice-cream social that will double as a fund-raiser for Blue Marble Dreams, a nonprofit that will train the drummers to open Butare’s first-ever ice-cream shop. Details about the project and the concert can be found online.