This problem is happening to me randomly since I started using Audacity under GNU/Linux (about 10 years ago). With version 2.1.2 it's still there.
When I select from main menu Transport > Rescan Audio Devices, Audacity has a big chance of crashing. I got used to that and I always save my work before using that option.
I guess it might have something to do with JACK audio server, as I'm using it all the time.
I tried reporting a bug, but seems that getting access to Audacity's bug tracking system is not easy, so I'm here.
I wasn't able to purposely reproduce this right now to give any more detail.
Can anybody confirm this behavior?
I'm running Linux Mint 18 KDE 5 64-bit at the moment.