Hang in umount in poudriere run

Hello,

I have hanging umount processes in the last two poudriere runs
on a 14.3p1 server.

See https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=288345

The umount processes can not be killed:

20104  2  D+       0:00.00 umount -f /pou/data/.m/143-default/21
20156  6- T+       0:00.00 umount -f /pou/data/.m/143-default/21/.p

Any ideas what I can do to debug this ?

-- 
pi@FreeBSD.org         +49 171 3101372                  Now what ?