instance stuck in starting, propolis zone fails to come up

On dogfood (rack2) after a mupdate to https://github.com/oxidecomputer/omicron/commit/020fde11e74b09202d6c53b491768bc4912903af
I have an instance that is stuck in starting.

The propolis zone responsible is on sled 23 (BRM42220016).
I see this zone has either started and failed in some way, or has never fully started:

BRM42220016 # zlogin oxz_propolis-server_f4019957-5d9d-45a0-97d8-e2c9c523a3e7
[Connected to zone 'oxz_propolis-server_f4019957-5d9d-45a0-97d8-e2c9c523a3e7' pts/3]
Last login: Sun Dec 15 02:50:00 on pts/3
The illumos Project     helios-2.0.23049        December 2024
root@oxz_propolis:~# svcs -x
svcs: Could not bind to repository server: repository server unavailable.  Exiting.
root@oxz_propolis:~# ps -ef 
     UID   PID  PPID   C    STIME TTY         TIME CMD
  netadm  9033  8945   0 01:15:01 ?           0:00 /lib/inet/ipmgmtd
    root  8962  8945   0 01:14:59 ?           0:00 /sbin/init
    root  9082  9081   0        - ?           0:00 <defunct>
    root  9237  9236   0        - ?           0:00 <defunct>
    root  8945  8945   0 01:14:59 ?           0:00 zsched
    root  9236  9079   0 01:15:27 ?           0:00 sulogin
    root  9079  8945   0 01:15:06 ?           0:00 /lib/svc/bin/svc.startd
    root  9081  9079   0 01:15:06 console     0:00 sulogin
  netcfg  9026  8945   0 01:15:01 ?           0:00 /lib/inet/netcfgd
    root 15039 15014   0 16:23:34 pts/3       0:00 ps -ef
    root 15013  8945   0 16:23:26 pts/3       0:00 /usr/bin/login -z global -f root
    root 15014 15013   0 16:23:26 pts/3       0:00 -bash

Start with the dogfood rack2 report, the mupdate commit, and the propolis zone on sled 23 (BRM42220016). Reproduce or inspect the failure using svcs -x and ps -ef inside the zone, then trace why the service repository is unavailable. Done means identifying the startup failure and verifying that the affected instance no longer remains stuck in starting.