python 2.6: RuntimeError: dictionary changed size during iteration

[kbandla]

From y.dmi...@gmail.com on July 06, 2010 12:00:21

Python 2.6.5 (release26-maint, Jun 23 2010, 10:41:00)
[GCC 4.3.4] on linux2
Type "help", "copyright", "credits" or "license" for more information.

import dpkt
Traceback (most recent call last):
File "", line 1, in
File "/usr/lib/python2.6/site-packages/dpkt/init.py", line 24, in
import ethernet
File "/usr/lib/python2.6/site-packages/dpkt/ethernet.py", line 128, in
load_types()
File "/usr/lib/python2.6/site-packages/dpkt/ethernet.py", line 122, in __load_types
mod = __import(modname, g)
File "/usr/lib/python2.6/site-packages/dpkt/ip6.py", line 95, in
import ip
File "/usr/lib/python2.6/site-packages/dpkt/ip.py", line 255, in
__load_protos()
File "/usr/lib/python2.6/site-packages/dpkt/ip.py", line 245, in __load_protos
for k, v in g.iteritems():
RuntimeError: dictionary changed size during iteration

Quick fix:
--- /usr/lib/python2.6/site-packages/dpkt/ip.py~ 2010-03-26 04:53:51.000000000 +0200
+++ /usr/lib/python2.6/site-packages/dpkt/ip.py 2010-07-06 18:54:05.013117134 +0300
@@ -242,7 +242,7 @@

XXX - auto-load IP dispatch table from IP_PROTO_* definitions

def __load_protos():
g = globals()

• for k, v in g.iteritems():
• for k, v in list(g.iteritems()):
  if k.startswith('IP_PROTO_'):
  name = k[9:].lower()
  try:

Original issue: http://code.google.com/p/dpkt/issues/detail?id=35

[kbandla]

From dugsong on January 06, 2011 07:45:41

I can't reproduce this?

[kbandla]

From jeggles...@gmail.com on March 01, 2011 13:13:25

I just ran into this on OS X.

[joe@deepwater-2:~]$ python -c 'import dpkt'
Traceback (most recent call last):
File "", line 1, in
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/dpkt/init.py", line 24, in
import ethernet
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/dpkt/ethernet.py", line 128, in
load_types()
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/dpkt/ethernet.py", line 122, in __load_types
mod = __import(modname, g)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/dpkt/ip6.py", line 95, in
import ip
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/dpkt/ip.py", line 255, in
__load_protos()
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/dpkt/ip.py", line 245, in __load_protos
for k, v in g.iteritems():
RuntimeError: dictionary changed size during iteration

However, it's not consistent. Not sure what triggers it.

[kbandla]

From joed...@gmail.com on September 12, 2012 13:53:26

Alternate fix:

--- dpkt/ip.py ( revision 84 )
+++ dpkt/ip.py (working copy)
@@ -2,6 +2,7 @@

"""Internet Protocol."""

+import copy
import dpkt

class IP(dpkt.Packet):
@@ -241,7 +242,7 @@

XXX - auto-load IP dispatch table from IP_PROTO_* definitions

def __load_protos():

• g = globals()
• g = copy.copy(globals())
  for k, v in g.iteritems():
  if k.startswith('IP_PROTO_'):
  name = k[9:].lower()

[kbandla]

From dan...@lacoon.com on May 13, 2013 01:59:26

So I had the same problem and I dug in and I notice that the problem is that the import in that loop is not relative. Meaning that you might import a non-relevant package by accident (in my case mtp).

The solution is:
@@ -246,7 +246,7 @@
if k.startswith('IP_PROTO_'):
name = k[9:].lower()
try:

•            mod = **import**(name, g)
  

•            mod = **import**(name, g, level=1)
       except ImportError:
           continue
       IP.set_proto(v, getattr(mod, name.upper()))
  

This should be commited to head

[kbandla]

A quick glance makes #61 seem to be a related issue

[kbandla]

Fixed in d7684fe. Tracked in #203