When re-running Packstack to install Heat as detailed on http://openstack.redhat.com/Deploy_Heat_and_launch_your_first_Application I got the following error:

Applying 192.168.142.2_osclient.pp
Applying 192.168.142.2_horizon.pp
Applying 192.168.142.2_heat.pp
192.168.142.2_osclient.pp :                 [ DONE ]                 
192.168.142.2_horizon.pp :                   [ DONE ]                
                                                                                             [ ERROR ]

ERROR : Error appeared during Puppet run: 192.168.142.2_heat.pp
Notice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns: IOError: [Errno 13] Permission denied: '/var/log/heat/heat-manage.log'
You will find full trace in log /var/tmp/packstack/20131129-195023-cRf7rn/manifests/192.168.142.2_heat.pp.log
Please check log file /var/tmp/packstack/20131129-195023-cRf7rn/openstack-setup.log for more information

On examination of the log file, I saw:

^[[mNotice: /Stage[main]/Heat/User[heat]/groups: groups changed '' to 'heat'^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns: Traceback (most recent call last):^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:   File "/usr/bin/heat-manage", line 34, in <module>^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:     manage.main()^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:   File "/usr/lib/python2.6/site-packages/heat/cmd/manage.py", line 81, in main^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:     log.setup("heat")^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:   File "/usr/lib/python2.6/site-packages/heat/openstack/common/log.py", line 359, in setup^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:     _setup_logging_from_conf()^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:   File "/usr/lib/python2.6/site-packages/heat/openstack/common/log.py", line 406, in _setup_logging_from_conf^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:     filelog = logging.handlers.WatchedFileHandler(logpath)^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:   File "/usr/lib64/python2.6/logging/handlers.py", line 377, in __init__^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:     logging.FileHandler.__init__(self, filename, mode, encoding, delay)^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:   File "/usr/lib64/python2.6/logging/__init__.py", line 827, in __init__^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:     StreamHandler.__init__(self, self._open())^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:   File "/usr/lib64/python2.6/logging/__init__.py", line 846, in _open^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns:     stream = open(self.baseFilename, self.mode)^[[0m
^[[mNotice: /Stage[main]/Heat::Db/Exec[heat-dbsync]/returns: IOError: [Errno 13] Permission denied: '/var/log/heat/heat-manage.log'^[[0m


It appears that there is an issue with a process trying to write to a log file they don't own.

Re-running Packstack resolved the issue, leading me to believe there's some kind of race condition going on.