My OpenCompute debug kit arrived today. Finally.
Below are a few photos of the $460** "OCP Debug Kit" that I ordered from Penguin Computing in Fremont, CA. The kit includes the tiny and very expensive OpenCompute debug board plus two relatively inexpensive custom cables. The debug board plugs into the standard OpenCompute debug port, and displays boot codes on two small numeric displays, and also presents a USB serial port that will get you console access.
A spend of $460 isn't much if you have a ton of these servers, but it's way too much if you are buying just one or two. Intel does publish the pin assignments for the debug port, so you can make your own serial cable.
Here is a photo of the full kit. Does it look like $460 worth of kit? No, but I'm just glad that this extremely specific gear is available, regardless of price.
No documentation is included. The tiny board plugs into the OCP debug port. What are the other two cables for? I have no idea.

Here is a rear view of one sled in one of the eBay OCP servers for reference. Note that there is no rear plate and no top cover, and that the disk cables pretty much just dangle there. Extreme minimalism.

Here is the debug board (outlined in blue) plugged into the debug port on the right side of the motherboard sled. Note the two single-digit displays, and the tiny USB port. There is also a small button that does - I don't know yet.
**
Debug Board, Quanta OCP 1 $349.99 $349.99
Cable, Serial, USB-mini-B/6-pin, Passive OCP Debug 1 $12.00 $12.00
Cable, Serial, USB-A/6x1 header, 3.3V, FTDI 1 $31.00 $31.00
Cable, Extender, 2x7/2x7, 20mm, OCP Debug 1 $4.00 $4.00
Subtotal $396.99
Est. Sales Tax $34.74
S & H (3rd Day) $28.54
QUOTE TOTAL $460.27