Hard lockup of scdaemon is observed.
"Hard" means that gpgconf --kill scdeamon cannot kill the process, but manual killing is required.
If it's not "hard", that is, the case where gpgconf --kill scdaemon can kill the process, it's considered fixed by T7386 (see T7378 and T7044).
This situation can be artificially created (even on POSIX machine), see T7323. Note that this situation is only under extreme scenario.
If it's clear that the lockup is due to the output non-consumption of client, please put information on T7323.
Otherwise, for other cases, please put information here.
If the log of Kleo (like the one in T7378) is available, it helps debugging.