(39/39) checking for file conflicts [#############################################################################] 100%
error: failed to commit transaction (conflicting files)
imath: /usr/lib/libImath-3_1.so.29 exists in filesystem
Errors occurred, no packages were upgraded.
https://forum.artixlinux.org/index.php/topic,4480.0.html
Is the answer just wait?
If the update is a point release you can delete that file and it will go through without much trouble, there are many such recompiles right now.
Not sure how you're getting this error. The previous forum topic you linked was something completely different (/usr/lib64 being used instead of /usr/lib).
Edit: However, the imath package mysteriously has a /usr/sr directory for some reason (??? thanks cmake). I did a rebuild real quick (3.1.9-1.1) that got rid of that so dunno if that will solve your problem OP.