Segfault with Gen2 18i20

[prg318]

When I run scarlett-mixer with a Scarlett 18i20 (gen2) attached, I get a segfault on Arch Linux:

$ scarlett-mixer 
zsh: segmentation fault (core dumped)  scarlett-mixer

I've attached an strace as well:
scarlett-mixer-18i20-strace.txt

Let me know if there is anything else I can do or provide to help troubleshoot the issue.
Thanks again for this project!

[prg318]

After re-reading the README; it looks like the gen2 18i20 isn't supported. I'm going to leave this open if anyone wants to clean up the error handling for this case, but feel free to close if you feel it's out of scope