Final Cut: The Making & Unmaking of Heaven’s Gate (2004)
https://www.youtube.com/watch?v=XnG-KZwrCxs - from the Cinema Garmonbozia YouTube channel (1 hr. and 16 mins.)

The blurb (from IMDb):
“An inside look at the hectic production of Heaven’s Gate (1980), the media circus that turned it into a synonym for movie flop and how it added to the tectonic change that occurred in Hollywood film studios after it infamously flopped.”

Backup link (playlist):
https://www.youtube.com/watch?v=hdcRiPLp4oU&list=PLA0E695232307E38E