F-spot has been removed from Ubuntu Vivid (15.04).
Dependency is not satisfiable: liblcms1 (>= 1.15-1)
None of the data for f-spot was gone, just the ability to run the application – probably something to do with mono library deprecation.
~$ find / -name f-spot 2>/dev/null
1.3MB in /home/g/.config/f-spot/photos.db
Anyway, opened Shotwell, “Import from Application”, “Import media from: F-Spot”, moving on.