Description of problem:
Noticed the following traceback after a package upgrade

Version-Release number of selected component (if applicable):
yum-2.9.6-1

How reproducible:
Always

Steps to Reproduce:
1.upgrade a package using yum
2.
3.

Actual results:
package upgrade properly, some traceback observed

Expected results:
no traceback

Additional info:

# yum upgrade pirut
Deprecated constant TYPE_INTERFACE during plugin initialization.
Please use TYPE_INTERACTIVE instead.
Loading "rhnplugin" plugin
Loading "installonlyn" plugin
This system is not registered with RHN.
RHN support will be disabled.
Setting up Upgrade Process
Setting up repositories
Reading repository metadata in from local files
Resolving Dependencies
--> Populating transaction set with selected packages. Please wait.
---> Downloading header for pirut to pack into transaction set.
pirut-1.1.12-1.noarch.rpm 100% |=========================|  20 kB    00:00
---> Package pirut.noarch 0:1.1.12-1 set to be updated
--> Running transaction check

Dependencies Resolved

=============================================================================
 Package                 Arch       Version          Repository        Size
=============================================================================
Updating:
 pirut                   noarch     1.1.12-1         development       191 k

Transaction Summary
=============================================================================
Install      0 Package(s)
Update       1 Package(s)
Remove       0 Package(s)

Total download size: 191 k
Is this ok [y/N]: y
Downloading Packages:
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Updating  : pirut                        ######################### [1/2]
  Cleanup   : pirut                        ######################### [2/2]
Traceback (most recent call last):
  File "/usr/bin/yum", line 29, in ?
    yummain.main(sys.argv[1:])
  File "/usr/share/yum-cli/yummain.py", line 180, in main
    base.doTransaction()
  File "/usr/share/yum-cli/cli.py", line 683, in doTransaction
    self.runTransaction(cb=cb)
  File "/usr/lib/python2.4/site-packages/yum/__init__.py", line 440, in
runTransaction
    self.plugins.run('posttrans')
  File "/usr/lib/python2.4/site-packages/yum/plugins.py", line 152, in run
    func(conduitcls(self, self.base, conf, **kwargs))
  File "/usr/lib/yum-plugins/rhnplugin.py", line 70, in posttrans_hook
    rhnPackageInfo.remoteDeltaPackages(delta)
  File "/usr/share/rhn/up2date_client/rhnPackageInfo.py", line 77, in
remoteDeltaPackages
    up2dateAuth.getSystemId(), pkgs)  File
"/usr/share/rhn/up2date_client/rpcServer.py", line 235, in doCall
    ret = apply(method, args, kwargs)
  File "/usr/lib/python2.4/xmlrpclib.py", line 1096, in __call__
    return self.__send(self.__name, args)
  File "/usr/share/rhn/up2date_client/rpcServer.py", line 45, in _request1
    ret = self._request(methodname, params)
  File "/usr/lib/python2.4/site-packages/rhn/rpclib.py", line 325, in _request
    request = self._req_body(params, methodname)
  File "/usr/lib/python2.4/site-packages/rhn/rpclib.py", line 232, in _req_body
    return xmlrpclib.dumps(params, methodname, encoding=self._encoding)
  File "/usr/lib/python2.4/xmlrpclib.py", line 1029, in dumps
    data = m.dumps(params)
  File "/usr/lib/python2.4/xmlrpclib.py", line 603, in dumps
    dump(v, write)
  File "/usr/lib/python2.4/xmlrpclib.py", line 615, in __dump
    f(self, value, write)
  File "/usr/lib/python2.4/xmlrpclib.py", line 619, in dump_nil
    raise TypeError, "cannot marshal None unless allow_none is enabled"
TypeError: cannot marshal None unless allow_none is enabled