Greg Kwedar never expected any of this. He never expected that his movie Sing Sing, which is back in theaters this weekend after a brief release last summer, would be generating awards-season buzz. His last film, 2016’s Transpecos, was a taut, tense border thriller that received positive reviews but failed to find a theatrical audience. He spent the years that followed producing similarly well-regarded indies and learning about a prison-theater organization called Rehabilitation Through the Arts, which went on to serve as the basis for Sing Sing. The film was acquired by the extremely hip indie distributor A24—the company behind Everything Everywhere All At Once, Lady Bird, Moonlight, and other movies that became the toasts of awards seasons—and stars veteran actor Colman Domingo, whose late-career renaissance…