Untitled Star Wars spin-off film

A Star Wars spin-off film was being worked on somewhere around the production of Solo: a Star Wars Story, but was cancelled.

Plot
Currently unknown, although it reportedly would have featured planet Tatooine, the home planet of Luke Skywalker

Why It Was Cancelled

 * 1) The only known reason as to why it was cancelled is because Solo was a box office flop.

Trivia

 * This spin-off may have been the fan-speculated Obi-Wan or Boba Fett film.