guava
-gwt 31.0 has a bug that prevents GWT compilation from working.
Other Guava artifacts aren't affected, only users of
GWT. (If you are using GWT, you would know it.)
Sorry for missing this during release: It was
a known issue, and we had a partial workaround in place, but I forgot to include the problem in the list of release blockers.
I expect to be able to get a fixed release out within the next day or two.