A friend sent me a photo of this Bolivian fruit called “ambaiba”:

I found one article about the fruit in Spanish, which says:

The ambaibo tree is much appreciated locally for its sweet and flavorful fruits. It is eaten as a fresh fruit and also is made into delicious marmalades. Its flavor resembles the fig, of which it is a distant relative.

It says the latin name is “cecropia polystachya.” It appears that this tree genus is called “embauba” in Portuguese and I think I've seen it in Rio, though I had no idea it had edible fruit. Or maybe the Rio version does not – pages talking about Brazilian “embauba” seem to typically mean “cecropia palmata” so it is probably a different species. (Though a few do mention polystachya as well. According to Portuguese Wikipedia “cecropia polystachya” is called “sambaiba-do-norte” or “embauba-da-mata” in Portuguese.)