there were a number of passes made prior to lynch being hired. the jodorowsky one with the documentary about it but also originally david lean and ridley scott. hr giger was part of the jodorowsky team and then with scott. the two would go on to make alien a couple of years later together. 

apparently lynch was not a sci-fi guy and hadnt read the book before being asked. he also chose this project over directing return of the jedi.