Before “Sing Sing” became a critical hit and awards darling, it almost failed to launch.

The film, which shows the positive impact that the real-life Rehabilitation Through the Arts (Rta) program has on a group of incarcerated men, features Colman Domingo as a playwright incarcerated after being wrongfully convicted of murder. Domingo is one of only three professional actors in the cast, which is otherwise made up alumni of the Rta program.

It’s an ambitious project by any measure, but filmmakers Clint Bentley, Greg Kwedar and Monique Walton realized — albeit a little late — that it would be near-impossible without industry support. “We just realized that about a month before we started shooting,” says Kwedar, who directed the film. “I remember having a legitimate panic attack.”

Mere weeks before filming was set to start in the summer of 2022, the team faced a race against the clock to find the right...