Python SNMP framework

Version: pysnmp 4.1.12a
Python: Python 2.5.4

The included example v3arch/agent/cmdrsp.py breaks with the following
exception when run on a 64-bit system:

Traceback (most recent call last):
File "./cmdrsp.py", line 10, in <module>
snmpEngine = engine.SnmpEngine()
File
"/home/bclark/.virtualenvs/snmp/lib/python2.5/site-packages/pysnmp/entity/e
ngine.py", line 16, in __init__
self.msgAndPduDsp = MsgAndPduDispatcher()
File
"/home/bclark/.virtualenvs/snmp/lib/python2.5/site-packages/pysnmp/proto/rf
c3412.py", line 23, in __init__
'SNMP-TARGET-MIB', 'SNMP-USER-BASED-SM-MIB'
File
"/home/bclark/.virtualenvs/snmp/lib/python2.5/site-packages/pysnmp/smi/buil
der.py", line 197, in loadModules
modData, sfx = mibSource.read(modName)
File
"/home/bclark/.virtualenvs/snmp/lib/python2.5/site-packages/pysnmp/smi/buil
der.py", line 47, in read
pycTime = struct.unpack('L', pycData[:4])[0]
File "/usr/lib/python2.5/struct.py", line 87, in unpack
return o.unpack(s)
struct.error: unpack requires a string argument of length 8