I've disabled all backends with the useclasse but the segfault still persists.
Created attachment 592748 [details]
Please attach a gdb backtrace of the faulty process.
Created attachment 592752 [details]
ok just found a solution for this.
Need to add use flag "threads" to the media-gfx/sane-backends.
After this it works. Still have problems with my brother scanner, but don't think thats another storry.
Bug can be closed now.