[john70t]

The greatest film that never was. It got to production stage and the studio halted it.
The story was remade by David Lynch.

Here is the documentary:
https://en.wikipedia.org/wiki/Jodorowsky's_Dune
In 1973, film producer Arthur P. Jacobs optioned the film rights to Dune but died before a film could be developed. The option was then taken over two years later by director Alejandro Jodorowsky, who proceeded to approach, among others, Virgin Records, with the prog rock groups Tangerine Dream, Gong and Mike Oldfield before settling on Pink Floyd and Magma for some of the music; artists H. R. Giger, Chris Foss, and Jean Giraud for set and character design; Dan O'Bannon for special effects; and Salvador Dalí, Orson Welles, Gloria Swanson, David Carradine, Mick Jagger, Amanda Lear, and others for the cast