Rrunning the test sudo ./test -c produces SD card errors in dmesg:

[33490.769029] mmcblk0: error -110 transferring data, sector 137216, nr 16, cmd response 0x900, card status 0xc00

More verbose log here: https://pastebin.com/AZUijQmW

This error will pop up every few minutes if I leave the test running just by itself. With my other processes running (full project: https://github.com/pinheadmz/ClockJr) these errors pop up as frequently as every few seconds.

My project displays the "rainbow wheel" effect for a few seconds then stops and goes blank. A few seconds later I will see this mmcblk0 error in dmesg.

I've been through FOUR SD CARDS, all different brands. It's not the card.