Applying the most recent batch of updates took excessively long on every system I updated.
On the last one, I apparently isolated it to "systemctl restart rpcbind.socket" stalling. This gets invoked by the rpcbind package's scripts:
root 9094 9068 0 10:14 tty2 00:00:00 /bin/systemctl restart rpcbind.socket root 9103 9017 0 10:14 pts/0 00:00:00 ps -fwu root [root@thinkpad system]# date Sat Dec 30 10:15:02 EST 2017
At that point, it's been sitting, doing nothing, for about a minute. Eventually whatever choked it finally unchoked, and the update continued.
Checking the status of this job:
● rpcbind.socket - RPCbind Server Activation Socket Loaded: loaded (/usr/lib/systemd/system/rpcbind.socket; enabled; vendor prese Active: active (running) since Sat 2017-12-30 10:17:21 EST; 39s ago
So, it finally got started @10:17. So, it took around three minutes for systemd to figure out how to close and reopen a couple of lousy sockets. That's all, apparently, what it had to do here. Amazing.