Armv7 unresponsive with flashing disk light

From: bob prohaska <fbsd_at_www.zefox.net>
Date: Fri, 25 Apr 2025 21:46:58 UTC 
A Pi2 running -current armv7 got stuck again during buildworld.
No debugger escape was possible, despite repeated tries. Power
cycle was followed by a normal boot.

This time, the usb hard disk activity LED was pulsing steadily,
roughly 3-5 Hz. That's new. Formerly all stoppages had no disk
activity indications. 

Thanks for reading,

bob prohaska