Writer’s block is traditionally not very cinematic. After all, movies are supposed to depict things happening, and this is specifically about something not happening. And yet, writer’s block is a theme the movies have returned to many times. Now, Ben Watts and Ivan Kander have curated cinema’s best moments of creative frustration into “Writer’s Block: A Super Cut.” Here, in four maddening minutes, are all of moviedom’s writers who can’t write. Or, at least, who can’t write at the moment. Poor Jack Nicholson comes down with this ailment in at least two movies, The Shining and As Good As It Gets. Other sufferers include Nicolas Cage in Adaptation, John Turturro in Barton Fink, Charlize Theron in Young Adult, and poor Billy Crystal in Throw Momma From The Train. (The word Crystal is looking for is “sultry,” but he never figures it out on his own.) Kander and Watts end their supercut on an optimistic note, however, with a series of scenes of writers conquering their respective blocks.