samba_dnsupdate crashed with RuntimeError in get_credentials(): kinit for INTEL$@REALM failed (Cannot contact any KDC for requested realm)

I confirm the bug for Quantal AMD64 :
I posted details here:
https://bugs.launchpad.net/ubuntu/+source/samba4/+bug/1049834

Ubuntu 13.04 affected.

Fixed in Samba 4.0.3?

Not using ubuntu, but this issue is happening to me and seemingly to a lot of folks.
I think I've found the cause.

In my case, it was a matter of incorrectly configured DNS causing creds.get_named_ccache()
to fail to find the KDC with which to obtain credentials. No core is being dumped in my case;
I was just getting this famous stack dump when trying to do:
    /usr/local/samba/sbin/samba_dnsupdate --verbose --all-names
as is suggested in the how-to I was reading to set up Samba.

A couple minutes with strace revealed that it was trying to look up vmnet-dc1.vmnet.us
using my upstream ISP's name server. At first I just put 127.0.0.1 in the /etc/krb.conf for
the kdc and admin_server settings in the [realms] section. This got me past the stacktrace
but I was stilling getting a lot of '. .. blah blah blah not found' errors. Then I realized that
I had left my ISP DNS in /etc/resolv.conf when I was wget-ing a needed source tarball, and
forgot to set it back to 127.0.0.1 (to use the samba-populated DNS server locally).
Herp derp derp! :) So I set resolv.conf to point at 127.0.0.1 and set krb5.conf to use the
correct DNS names for kdc, etc. Bingo! It now works perfectly.

Bottom line with this "bug" I think is that you need to be VERY careful to set up DNS
right or things will fail. (DNS tends to be that way)

/etc/resolv.conf:
------------ snip snip -------------------
search vmnet.us
nameserver 127.0.0.1
------------ snip snip -------------------

/etc/krb5.conf
------------ snip snip -------------------
[logging]
 default = FILE:/var/log/krb5libs.log
 kdc = FILE:/var/log/krb5kdc.log
 admin_server = FILE:/var/log/kadmind.log

[libdefaults]
 default_realm = VMNET.US
 dns_lookup_realm = false
 dns_lookup_kdc = true
 ticket_lifetime = 24h
 renew_lifetime = 7d
 forwardable = true

[realms]
 VMNET.US = {
  kdc = vmnet-dc1.vmnet.us
  admin_server = vmnet-dc1.vmnet.us
 }

[domain_realm]
 .vmnet.us = VMNET.US
 vmnet.us = VMNET.US
------------ snip snip -------------------

Also affecting 13.04. Using internal DNS server. Setting the nameserver to 127.0.0.1 doesn't fix because the records are not present in the internal DNS server.

Distributor ID: Ubuntu
Description: Ubuntu 13.04
Release: 13.04
Codename: raring

Linux <hostname> 3.8.0-19-generic #29-Ubuntu SMP Wed Apr 17 18:19:42 UTC 2013 i686 i686 i686 GNU/Linux

ii libsamba-credentials0:i386 4.0.0+dfsg1-1ubuntu1 i386 Samba Credentials management library
ii libsamba-hostconfig0:i386 4.0.0+dfsg1-1ubuntu1 i386 Samba host configuration library
ii libsamba-policy0:i386 4.0.0+dfsg1-1ubuntu1 i386 Samba policy management
ii libsamba-util0:i386 4.0.0+dfsg1-1ubuntu1 i386 Samba utility function library
ii python-samba 4.0.0+dfsg1-1ubuntu1 i386 Python bindings for Samba
ii samba-common 2:3.6.9-1ubuntu1 all common files used by both the Samba server and client
ii samba-common-bin 2:3.6.9-1ubuntu1 i386 common files used by both the Samba server and client
ii samba-dsdb-modules 4.0.0+dfsg1-1ubuntu1 i386 Samba Directory Services Database
ii samba4 4.0.0+dfsg1-1ubuntu1 i386 SMB/CIFS file, NT domain and active directory server (version 4)
ii samba4-common-bin 4.0.0+dfsg1-1ubuntu1 i386 Samba 4 common files used by both the server and the client

  /usr/sbin/samba_dnsupdate: Traceback (most recent call last):
[2013/07/27 00:51:36, 0] ../lib/util/util_runcmd.c:334(samba_runcmd_io_handler)
  /usr/sbin/samba_dnsupdate: File "/usr/sbin/samba_dnsupdate", line 507, in <module>
[2013/07/27 00:51:36, 0] ../lib/util/util_runcmd.c:334(samba_runcmd_io_handler)
  /usr/sbin/samba_dnsupdate: get_credentials(lp)
[2013/07/27 00:51:36, 0] ../lib/util/util_runcmd.c:334(samba_runcmd_io_handler)
  /usr/sbin/samba_dnsupdate: File "/usr/sbin/samba_dnsupdate", line 121, in get_credentials
[2013/07/27 00:51:36, 0] ../lib/util/util_runcmd.c:334(samba_runcmd_io_handler)
  /usr/sbin/samba_dnsupdate: creds.get_named_ccache(lp, ccachename)
[2013/07/27 00:51:36, 0] ../lib/util/util_runcmd.c:334(samba_runcmd_io_handler)
  /usr/sbin/samba_dnsupdate: RuntimeError: kinit for <hostname>$@<DOMAIN.LOCAL> failed (Cannot contact any KDC for requested realm)