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
For the most part, the plot is 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.