[2.0a4] maas-rackd missing presumed lost

After updating to MAAS 2.0a4 I seem to have lost maas-rackd, but I'm not sure where.

systemd suggests maas-rackd is running although there is an error in its logs related to PAM-CGFS that I don't understand:

mark@maas:/var/log/maas$ sudo service maas-rackd status
[sudo] password for mark:
● maas-rackd.service - MAAS Cluster Controller
   Loaded: loaded (/lib/systemd/system/maas-rackd.service; enabled; vendor preset: enabled)
   Active: active (running) since Wed 2016-03-30 11:21:36 BST; 4min 32s ago
     Docs: https://maas.ubuntu.com/
  Process: 2885 ExecStartPre=/bin/rm -f /var/lib/maas/dhcpd6.conf (code=exited, status=0/SUCCESS)
  Process: 2865 ExecStartPre=/bin/rm -f /var/lib/maas/dhcpd.conf (code=exited, status=0/SUCCESS)
  Process: 2834 ExecStartPre=/bin/rm -f /var/lib/maas/dhcpd.sock (code=exited, status=0/SUCCESS)
 Main PID: 2889 (sh)
    Tasks: 8 (limit: 512)
   Memory: 83.4M
      CPU: 11.283s
   CGroup: /system.slice/maas-rackd.service
           ├─2889 /bin/sh -c exec /usr/bin/authbind --deep /usr/bin/twistd3 --nodaemon --pidfile= maas-rackd 2>&1 | tee -a $LOGFILE
           ├─2892 /usr/bin/python3 /usr/bin/twistd3 --nodaemon --pidfile= maas-rackd
           └─2893 tee -a /var/log/maas/rackd.log

Mar 30 11:24:46 maas sudo[4495]: maas : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/systemctl status maas-dhcpd6
Mar 30 11:24:46 maas sudo[4495]: pam_unix(sudo:session): session opened for user root by (uid=0)
Mar 30 11:25:37 maas sudo[4529]: maas : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/systemctl status maas-dhcpd6
Mar 30 11:25:37 maas sudo[4529]: pam_unix(sudo:session): session opened for user root by (uid=0)
Mar 30 11:25:37 maas sudo[4530]: maas : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/systemctl status tgt
Mar 30 11:25:37 maas sudo[4530]: pam_unix(sudo:session): session opened for user root by (uid=0)
Mar 30 11:25:37 maas sudo[4531]: maas : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/systemctl status maas-dhcpd
Mar 30 11:25:37 maas sudo[4531]: pam_unix(sudo:session): session opened for user root by (uid=0)
Mar 30 11:25:37 maas PAM-CGFS[4531]: Failed to create a cgroup for user root
Mar 30 11:25:37 maas sudo[4531]: pam_unix(sudo:session): session closed for user root

However there are no log files for it:

mark@maas:/var/log/maas$ ls -l
total 54456
lrwxrwxrwx 1 root root 16 Mar 29 09:53 apache2 -> /var/log/apache2
-rw-r--r-- 1 syslog syslog 18350 Mar 30 11:24 maas.log
-rw-r--r-- 1 syslog syslog 104904 Mar 30 06:36 maas.log.1
-rw-r--r-- 1 syslog syslog 20516 Mar 29 06:23 maas.log.2.gz
drwxr-x--- 2 proxy proxy 4096 Mar 30 06:38 proxy
-rw-r--r-- 1 maas maas 55591104 Mar 30 11:26 regiond.log
drwxr-xr-x 2 syslog syslog 4096 Mar 28 20:24 rsyslog

It looks like many of the services are up:

tcp 0 0 *:5248 *:* LISTEN 2892/python3
tcp 0 0 *:5250 *:* LISTEN 2815/python3
tcp 0 0 *:5251 *:* LISTEN 2822/python3
tcp 0 0 *:5252 *:* LISTEN 2807/python3
tcp 0 0 *:3109 *:* LISTEN 3097/conserver
tcp 0 0 *:5253 *:* LISTEN 2811/python3
tcp 0 0 *:7911 *:* LISTEN 3625/dhcpd
tcp 0 0 *:40455 *:* LISTEN 3099/conserver
tcp 0 0 maas.mallards:domain *:* LISTEN 2770/named
tcp 0 0 localhost:domain *:* LISTEN 2770/named
tcp 0 0 *:ssh *:* LISTEN 2844/sshd
tcp 0 0 *:5240 *:* LISTEN 2815/python3
tcp 0 0 *:5240 *:* LISTEN 2811/python3
tcp 0 0 *:5240 *:* LISTEN 2807/python3
tcp 0 0 *:5240 *:* LISTEN 2822/python3
tcp 0 0 *:3128 *:* LISTEN 2899/squid3
tcp 0 0 localhost:postgresql *:* LISTEN 2411/postgres
tcp 0 0 localhost:smtp *:* LISTEN 3571/master
tcp 0 0 localhost:953 *:* LISTEN 2770/named
tcp 0 0 localhost:954 *:* LISTEN 2770/named
tcp 0 0 *:iscsi-target *:* LISTEN 2794/tgtd
tcp6 0 0 [::]:8000 [::]:* LISTEN 2899/squid3
tcp6 0 0 [::]:http [::]:* LISTEN 3437/apache2
tcp6 0 0 [::]:domain [::]:* LISTEN 2770/named
tcp6 0 0 [::]:ssh [::]:* LISTEN 2844/sshd
tcp6 0 0 localhost:postgresql [::]:* LISTEN 2411/postgres
tcp6 0 0 localhost:smtp [::]:* LISTEN 3571/master
tcp6 0 0 [::]:iscsi-target [::]:* LISTEN 2794/tgtd

However commissioning is not succeeding and the absence of rackd logs makes it a little difficult to debug :)