In 1980, renowned Russian animators Yuri Norstein and Francheska Yarbusova began production on a beautiful stop-motion film called The Overcoat. After 40 years of work, the film remains unfinished, and The Overcoat has taken the record for longest animation production of all time.
The Animators Who've Spent 40 Years on a Single Film (2021) is currently not available on any services.