I was something of a Dirk Pitt fan in my teens, I've got 18 of the Dirk Pitt books (also five of the Isaac Bell series and one Oregon Files books, I have a whole Cussler section) including Sahara. It's the 11th book in the Dirk Pitt series.
It's the second attempt at a Dirk Pitt movie, in 1980 they adapted the fourth book, Raise The Titanic. It's even worse.
At first glance it might be easy to picture a series of movies based on Dirk Pitt books, but if you start thinking about it, 1. the books are all pretty formulaic, same general plot of handsome tall guy punches a captain planet villain and rescues the treasure/women, 2. Sahara is one of the more straightforward ones to film; other books you'll need much weirder settings varying from the ocean depths to the surface of the moon at one point, 3. each book is a bigger story than will fit in a movie. A bunch of stuff had to be trimmed out of Sahara to make the movie, kind of like they did with The Martian.
There's also a lot of shit that went wrong behind the scenes, the budget exploded, apparently there were bribes paid to the Moroccan government, and Cussler and the production company sued each other, with Cussler losing to the tune of $20 million.
All in order to produce a movie that lost its ass at the box office and failed to make any cultural impact at all.
Roundup is an herbicide, not a pesticide.