Linux Lite Forums

Software - Support => Updates => Topic started by: starnekit on January 01, 2024, 09:21:27 AM

Title: No module named 'apt_pkg'
Post by: starnekit on January 01, 2024, 09:21:27 AM

Hello! I've tried to update several times with "sudo apt update", but anytime I have the same error with apt_pkg
Does anyone knows what the problem it could be?

For extra info - I installed some freshly versions of Python, maybe it broke the update system?

Thank you very much!

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===========================
Install Updates Error log
===========================
Install Updates could not fetch the package cache information lists.
Go to https://www.linuxliteos.com/forums/ and paste the log below into the Software - Support - Updates section for assistance.

============ Log ===========

Сущ:1 https://repo.steampowered.com/steam stable InRelease
Сущ:2 http://security.ubuntu.com/ubuntu jammy-security InRelease
Сущ:3 http://packages.microsoft.com/repos/code stable InRelease
Сущ:4 http://archive.canonical.com/ubuntu jammy InRelease
Сущ:5 https://dl.google.com/linux/chrome/deb stable InRelease
Сущ:6 http://repo.linuxliteos.com/linuxlite fluorite InRelease
Сущ:7 https://ppa.launchpadcontent.net/deadsnakes/ppa/ubuntu jammy InRelease
Сущ:8 http://us.archive.ubuntu.com/ubuntu jammy InRelease
Сущ:9 http://us.archive.ubuntu.com/ubuntu jammy-updates InRelease
Сущ:10 http://us.archive.ubuntu.com/ubuntu jammy-backports InRelease
Traceback (most recent call last):
  File "/usr/lib/cnf-update-db", line 3, in <module>
    import apt_pkg
ModuleNotFoundError: No module named 'apt_pkg'
Чтение списков пакетов…
E: Problem executing scripts APT::Update::Post-Invoke-Success 'if /usr/bin/test -w /var/lib/command-not-found/ -a -e /usr/lib/cnf-update-db; then /usr/lib/cnf-update-db > /dev/null; fi'
E: Sub-process returned an error code


Title: Re: No module named 'apt_pkg'
Post by: stevef on January 02, 2024, 12:49:36 AM

It is possible that changing the python version has caused many function scripts to stop working.

What do these commands indicate ?

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inxi -S

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python3 -V

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ls -l /usr/bin/python*

Title: Re: No module named 'apt_pkg'
Post by: starnekit on January 02, 2024, 12:59:00 PM

Thanks for the answer!

Those commands indicates:

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inxi -S

System:
  Host: linux-laptop1 Kernel: 5.15.0-91-generic x86_64 bits: 64
  Desktop: Xfce 4.16.0 Distro: Linux Lite 6.6 LTS


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python3 -V

Python 3.11.7


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ls -l /usr/bin/python*

lrwxrwxrwx 1 root root      24 дек 17 20:46 /usr/bin/python -> /etc/alternatives/python
lrwxrwxrwx 1 root root      25 дек 18 00:12 /usr/bin/python3 -> /etc/alternatives/python3
-rwxr-xr-x 1 root root 5904904 ноя 20 18:14 /usr/bin/python3.10
lrwxrwxrwx 1 root root      34 ноя 20 18:14 /usr/bin/python3.10-config -> x86_64-linux-gnu-python3.10-config
-rwxr-xr-x 1 root root 6714392 дек  8 21:56 /usr/bin/python3.11
lrwxrwxrwx 1 root root      17 дек 17 20:46 /usr/bin/python3-config -> python3.10-config
-rwxr-xr-x 1 root root     960 янв 25  2023 /usr/bin/python3-futurize
-rwxr-xr-x 1 root root     964 янв 25  2023 /usr/bin/python3-pasteurize


Title: Re: No module named 'apt_pkg'
Post by: stevef on January 02, 2024, 01:25:08 PM

The required system default python for Linux Lite 6.6 is 3.10.

What instructions did you follow to install python 3.11 ?
If python 3.11 became system default during the install, is almost certainly the cause of the problem.

Title: Re: No module named 'apt_pkg'
Post by: starnekit on January 02, 2024, 06:06:13 PM

Quote

What instructions did you follow to install python 3.11 ?

I searched in my browser history

Seems like I used this guide https://www.itsupportwale.com/blog/how-to-upgrade-to-python-3-11-on-ubuntu-20-04-and-22-04-lts/ (https://www.itsupportwale.com/blog/how-to-upgrade-to-python-3-11-on-ubuntu-20-04-and-22-04-lts/) which connected with using "deadsnakes" repo

I think it closely correlates with the problems people had in this thread https://stackoverflow.com/questions/13708180/python-dev-installation-error-importerror-no-module-named-apt-pkg (https://stackoverflow.com/questions/13708180/python-dev-installation-error-importerror-no-module-named-apt-pkg)

So as I understand I should move the apt_pkg into the never Python folder or maybe say Linux to use python 3.10 as the default again, right?

Title: Re: No module named 'apt_pkg'
Post by: starnekit on January 02, 2024, 06:57:31 PM

Ok, I think I fixed it!

I used

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sudo update-alternatives --config python3 than chose the 3.10 version and finally apt update works again!

I want to believe I used the right way

Title: Re: No module named 'apt_pkg'
Post by: stevef on January 03, 2024, 03:25:08 AM

You can have different versions of python in parallel on your system, but if the system default is changed it is likely to cause problems.

The worrying bit in the instructions you linked to is

Quote

.... and configure it as the default version of Python in Ubuntu 20.04 and 22.04 LTS.

This should come with a warning really.
The comments under the instructions show that others also had problems after following the instructions.

Quote

I want to believe I used the right way

It was necessary to reverse whatever was done to change the system default - so step 4 of the instruction needed to be undone which you did.

Title: Re: No module named 'apt_pkg'
Post by: starnekit on January 03, 2024, 08:57:01 AM

Thanks a lot for your help! :D