if you look at the summary and the master logs, you can see that the master hasn't received any results from betty-arcnext-paladin.  so you should see where that communication broke down.

I will try to narrow down the cause, but I still won't know how to fix it.

It's the CIDB hang from issue 890053. I will use gdb to send a socket close event to the hung process. That will rescue the build.

Alec killed the master paladin. The run results were lost but the immediate issue was fixed. The next run should be fine; this happens every few months. We should be completely off of CIDB in two quarters.