[Bug]: Check not working with Python 3.12 after Ubuntu 24.04. upgrade

[log1-c]

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• Yes, I've searched similar issues on GitHub and didn't find any.

Which version contains the bug?

1.2.0

Describe the bug

Hello :)

After upgrading to Ubuntu 24.04 which comes with python3.12 the script stopped working.

First error message was

Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/pysnmp/smi/builder.py", line 18, in PY_MAGIC_NUMBER = importlib.util.MAGIC_NUMBER ^^^^^^^^^^^^^^ AttributeError: module 'importlib' has no attribute 'util' During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/usr/lib/python3/dist-packages/pysnmp/smi/builder.py", line 23, in raise ImportError() ImportError During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/usr/lib/nagios/plugins/check_hwgroup.py", line 25, in from pysnmp.entity.rfc3413.oneliner import cmdgen File "/usr/lib/python3/dist-packages/pysnmp/entity/rfc3413/oneliner/cmdgen.py", line 10, in from pysnmp.hlapi.asyncore import * File "/usr/lib/python3/dist-packages/pysnmp/hlapi/init.py", line 9, in from pysnmp.smi.rfc1902 import * File "/usr/lib/python3/dist-packages/pysnmp/smi/rfc1902.py", line 10, in from pysnmp.smi.builder import ZipMibSource File "/usr/lib/python3/dist-packages/pysnmp/smi/builder.py", line 26, in import imp ModuleNotFoundError: No module named 'imp'

I then created a venv and installed the requirements and pysnmp in the most recent version

/opt/check_hwgroup# ./bin/pip freeze
certifi==2026.5.20
charset-normalizer==3.4.7
idna==3.17
nagiosplugin==1.3.3
ply==3.11
pyasn1==0.6.3
pyasyncore==1.0.4
pycryptodomex==3.23.0
pysnmp==7.1.27
pysnmp-pyasn1==1.1.3
pysnmp-pysmi==1.1.12
pysnmplib==5.0.24
requests==2.34.2
urllib3==2.7.0

This makes the script return

Error: Please call .create() to construct UdpTransportTarget object

I then tried downgrading pysnmp to a version < 5

# ./bin/pip install "pysnmp<5"
Collecting pysnmp<5
  Downloading pysnmp-4.4.12-py2.py3-none-any.whl.metadata (1.8 kB)
Collecting pysmi (from pysnmp<5)
  Downloading pysmi-2.0.0-py3-none-any.whl.metadata (3.9 kB)
Requirement already satisfied: pycryptodomex in ./lib/python3.12/site-packages (from pysnmp<5) (3.23.0)
Requirement already satisfied: pyasn1>=0.2.3 in ./lib/python3.12/site-packages (from pysnmp<5) (0.6.3)
Collecting Jinja2>=3.1.3 (from pysmi->pysnmp<5)
  Downloading jinja2-3.1.6-py3-none-any.whl.metadata (2.9 kB)
Collecting lark>=1.1.9 (from pysmi->pysnmp<5)
  Downloading lark-1.3.1-py3-none-any.whl.metadata (1.8 kB)
Requirement already satisfied: requests>=2.26.0 in ./lib/python3.12/site-packages (from pysmi->pysnmp<5) (2.34.2)
Collecting MarkupSafe>=2.0 (from Jinja2>=3.1.3->pysmi->pysnmp<5)
  Downloading markupsafe-3.0.3-cp312-cp312-manylinux2014_x86_64.manylinux_2_17_x86_64.manylinux_2_28_x86_64.whl.metadata (2.7 kB)
Requirement already satisfied: charset_normalizer<4,>=2 in ./lib/python3.12/site-packages (from requests>=2.26.0->pysmi->pysnmp<5) (3.4.7)
Requirement already satisfied: idna<4,>=2.5 in ./lib/python3.12/site-packages (from requests>=2.26.0->pysmi->pysnmp<5) (3.17)
Requirement already satisfied: urllib3<3,>=1.26 in ./lib/python3.12/site-packages (from requests>=2.26.0->pysmi->pysnmp<5) (2.7.0)
Requirement already satisfied: certifi>=2023.5.7 in ./lib/python3.12/site-packages (from requests>=2.26.0->pysmi->pysnmp<5) (2026.5.20)
Downloading pysnmp-4.4.12-py2.py3-none-any.whl (296 kB)
   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 296.5/296.5 kB 816.1 kB/s eta 0:00:00
Downloading pysmi-2.0.0-py3-none-any.whl (87 kB)
   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 87.2/87.2 kB 954.2 kB/s eta 0:00:00
Downloading jinja2-3.1.6-py3-none-any.whl (134 kB)
   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 134.9/134.9 kB 2.1 MB/s eta 0:00:00
Downloading lark-1.3.1-py3-none-any.whl (113 kB)
   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 113.2/113.2 kB 1.6 MB/s eta 0:00:00
Downloading markupsafe-3.0.3-cp312-cp312-manylinux2014_x86_64.manylinux_2_17_x86_64.manylinux_2_28_x86_64.whl (22 kB)
Installing collected packages: MarkupSafe, lark, Jinja2, pysmi, pysnmp
  Attempting uninstall: pysnmp
    Found existing installation: pysnmp 7.1.27
    Uninstalling pysnmp-7.1.27:
      Successfully uninstalled pysnmp-7.1.27
Successfully installed Jinja2-3.1.6 MarkupSafe-3.0.3 lark-1.3.1 pysmi-2.0.0 pysnmp-4.4.12
root@icinga2-ihk-si:/opt/check_hwgroup# ./bin/pip install "pysnmp"
Requirement already satisfied: pysnmp in ./lib/python3.12/site-packages (4.4.12)
Requirement already satisfied: pysmi in ./lib/python3.12/site-packages (from pysnmp) (2.0.0)
Requirement already satisfied: pycryptodomex in ./lib/python3.12/site-packages (from pysnmp) (3.23.0)
Requirement already satisfied: pyasn1>=0.2.3 in ./lib/python3.12/site-packages (from pysnmp) (0.6.3)
Requirement already satisfied: Jinja2>=3.1.3 in ./lib/python3.12/site-packages (from pysmi->pysnmp) (3.1.6)
Requirement already satisfied: lark>=1.1.9 in ./lib/python3.12/site-packages (from pysmi->pysnmp) (1.3.1)
Requirement already satisfied: requests>=2.26.0 in ./lib/python3.12/site-packages (from pysmi->pysnmp) (2.34.2)
Requirement already satisfied: MarkupSafe>=2.0 in ./lib/python3.12/site-packages (from Jinja2>=3.1.3->pysmi->pysnmp) (3.0.3)
Requirement already satisfied: charset_normalizer<4,>=2 in ./lib/python3.12/site-packages (from requests>=2.26.0->pysmi->pysnmp) (3.4.7)
Requirement already satisfied: idna<4,>=2.5 in ./lib/python3.12/site-packages (from requests>=2.26.0->pysmi->pysnmp) (3.17)
Requirement already satisfied: urllib3<3,>=1.26 in ./lib/python3.12/site-packages (from requests>=2.26.0->pysmi->pysnmp) (2.7.0)
Requirement already satisfied: certifi>=2023.5.7 in ./lib/python3.12/site-packages (from requests>=2.26.0->pysmi->pysnmp) (2026.5.20)
root@icinga2-ihk-si:/opt/check_hwgroup# ./bin/pip freeze
certifi==2026.5.20
charset-normalizer==3.4.7
idna==3.17
Jinja2==3.1.6
lark==1.3.1
MarkupSafe==3.0.3
nagiosplugin==1.3.3
ply==3.11
pyasn1==0.6.3
pyasyncore==1.0.4
pycryptodomex==3.23.0
pysmi==2.0.0
pysnmp==4.4.12
pysnmp-pyasn1==1.1.3
pysnmp-pysmi==1.1.12
pysnmplib==5.0.24
requests==2.34.2
urllib3==2.7.0

but this leads to the same traceback like the first one.

Doing a upgrade of all required modules ./bin/pip install nagiosplugin pysnmplib pyasyncore --upgrade produces

Traceback (most recent call last): File "/usr/lib/nagios/plugins/check_hwgroup.py", line 25, in from 
pysnmp.entity.rfc3413.oneliner import cmdgen ModuleNotFoundError: No module named 'pysnmp.entity.rfc3413.oneliner'

And changeing that line to import cmdgen only and installing the cmdgen module doesn't work either, the traceback remains

Traceback (most recent call last): File "/usr/lib/nagios/plugins/check_hwgroup.py", line 26, in import cmdgen ModuleNotFoundError: No module named 'cmdgen'

Could you have a look at it?

How to recreate the bug?

Upgrade from Ubuntu 22.04 to Ubuntu 24.04.

[martialblog]

Hi, thanks for the hint.

Might be related to pysnmp/pysnmp#56 but we need to investigate it. If you have any further information let us now.

[martialblog]

We started working on an update here #19

[martialblog]

Hi,

We have discussed the future of the plugin internally and we have decided to move to Golang to improve maintainability and simplify usage.

The functionality will be the same.

I have started working on this here: #21

Most of the work is done and the plugins works similar to the Python version.
I want to add SNMPv3 support and then we will have a release.