Steps to repro:
Start a new scene in Voxel Mode
Add a cube primitive (don't forget to Apply it)
Select the Build Tool and assign it to a hotkey (I used F8)
Select the Pose Tool and assign it to a hotkey (I STACKED it on F8)
Hit F8 a couple times to rapidly toggle between these two tools.
Crash occurs during the toggle.
As far as I know, 3DC has Linux support. I wonder why it's not available on Steam? The result is that I can't install 3DC on my Ubuntu, which is rather sad =(