Comment 12 for bug 1437930

The viewer worked for me as of yesterday's build, but when I downloaded today's nightly it broke. To be clear, nothing changed about the PCB file overnight.

Backtrace attached, project files available here: https://github.com/tessel/tessel-v2-hardware (commit hash 10bb7155e8dc4be78932c26390652a3ad72f7c0b)