I'll be doing a build of this and latest stable indilib tonight so no comments on the 2.9.3 itself, however, when I went to check the git repo out, the tags are a little confusing.
Latest stable is v2.9.3 yet there's v3.x.x and v4.x.x as well as v16/17 etc. I assume the latter are for ubuntu but what are the v3.x and v4.x tags? They're several years old so not the latest, which makes the version numbering odd?