Cannot open terminal, panel missing after python install [Solved]

[shesanp]

Hello!

I recently installed a newer version of Python on my Linux mint 18 cinammon. I upgraded the existing version (3.2?) with 3.6 if I'm not mistaken. I had not rebooted my pc sonce doing that, and today when I did my bottom panel with the start menu is missing. I cannot run the terminal, or run any program. The file manager works as root, but it's pretty weird as it is unmovable and stuck on the right top side, and does not have a proper header and close, maximize and minimize buttons.
I found a post on the forum with a similar problem, which apparently was fixed when the python version was reverted, but I can't really do that since the terminal does not work.

Sorry about the hazy details on python versions. I don't remember correctly and there's no way for me to check right now. I have also attached a couple images to show the desktop and file manager. Any help would be much appreciated!

[WharfRat]

I recently installed a newer version of Python on my Linux mint 18 cinammon. I upgraded the existing version (3.2?) with 3.6 if I'm not mistaken.s to show the desktop and file manager.

Hello shesanp

Welcome to Linux Mint and the Linux Mint forum

A lot of applications are dependent on the included versions of python, as you have just discovered.

How did you install the newer version of python

[shesanp]

I followed this tutorial:

https://mintguide.org/other/794-python- ... -mint.html

Basically just added the repository, then sudo install.
To use 3.6 instead of the older one, I used these commands:

sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.5 1
sudo update-alternatives --install /usr/bin/

update-alternatives --list python3

#and then...

sudo update-alternatives --config python3

Now that I look at the instructions again, it seems like I did exactly what the tutorial author told to not do, ie. mess with the older python2.7 assignment.

How can I remedy this? Guess I could reinstall the OS again, but I'd like to get my hands dirty and learn something in the process as well

[WharfRat]

OK, getting rid of something installed via the repo is easier than a manually installed package.

Start with sudo apt-get purge python3.6

You'll have to do this from a tty console so press ctl-alt-f1 to enter one - login with your user name and password.

You can switch back to the desktop by pressing ctl-alt-f7 or f8.

Also make note of ls -lh /etc/alternatives/|grep python3

Type that carefully as these symlinks need to be removed.

Lets see how far this takes you.

[shesanp]

removing the package worked. i ended up doing

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sudo apt-get autoremove 

as well.

I ran the second command after that and got this response :

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lrwxrwxrwx 1 root root   18 Nov 10 15:25 python3 
-| /usr/bin/python3.6 

-| was actually in the form of an arrow, but i don't have the symbol for the slanted triangle...


The desktop is in the same state.

What is the function of ls -lh command?
Also, is there a way to open a software through the tty console? I tried :

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enter google-chrome-stable

to get my browser running, but to no avail.

[WharfRat]

Go back to the tty session and enter sudo update-alternatives --config python3

If you have choices, choose /usr/bin/python3.5

Let me know

[shesanp]

This is the result:

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update alternatives: warning: /etc/alternatives/python3 is dangling; it will be updated with best choice
There is only one alternative in link group python3 (providing /usr/bin/python3): /usr/bin/python3): /usr/bin/python3.6
Nothing to configure.

[WharfRat]

Well I guess it doesn't want to make this easy so instead of doing this from the tty, boot your linux mint installation flash/dvd and mount your linux partition to /mnt.

Then list the /mnt/usr/bin folder with ls -lh /mnt/usr/bin/pyth* and ls -lh /mnt/etc/alternatives/|grep python

If you don't know how to mount your linux partition, paste back sudo blkid

I forgot to to explain that ls -lh is just listing files in a long human readable format form e.g., 1K 234M 2G.

[shesanp]

Thanks! I tried the following, as per your instructions:

• Booted the Linux Mint 18 USB drive to a live session.

• Ran sudo blkid in terminal to get this result:

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  /dev/sda1: UUID="6EE2-DF64" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="60fe439f-bfe2-48c5-bbfc-733dd394a5bb"
  /dev/sda2: UUID="cfa95f00-d5d2-4bf6-a95c-149012a01ce9" TYPE="ext4" PARTUUID="4ce8b762-83a8-4dcf-bee6-a06307262bd5"
  /dev/loop0: TYPE="squashfs"
  /dev/sda3: UUID="65be0a97-3e72-48f9-885b-15346dd51afb" TYPE="swap" PARTUUID="e4ac5867-dc89-47e9-9d58-e1139e5fd273"
  /dev/sdb1: UUID="2017-06-28-15-44-43-00" LABEL="Linux Mint 18.2 Cinnamon 64-bit" TYPE="iso9660" PTUUID="08a2574b" PTTYPE="dos" PARTUUID="08a2574b-01"
  /dev/sdb2: SEC_TYPE="msdos" UUID="E561-C446" TYPE="vfat" PARTUUID="08a2574b-02"
  

• I gathered that the partition that I need to mount to /mnt is /dev/sda2 since that is where the linux filesystem is. Is that right?

• Ran the

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   sudo mount -t auto -v /dev/sda2 /mnt 

  command.

• Result:

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   mount: /dev/sda2 mounted on /mnt. 

• Ran the

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   ls -lh /mnt/usr/bin/pyth* 

  command.

• Result:

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   lrwxrwxrwx 1 root root    9 Apr  2  2017 /mnt/usr/bin/python -> python2.7
  lrwxrwxrwx 1 root root    9 Apr  2  2017 /mnt/usr/bin/python2 -> python2.7
  -rwxr-xr-x 1 root root 3.4M Nov 19  2016 /mnt/usr/bin/python2.7
  lrwxrwxrwx 1 root root   25 Nov 10 20:25 /mnt/usr/bin/python3 -> /etc/alternatives/python3
  -rwxr-xr-x 1 root root 4.3M Nov 17  2016 /mnt/usr/bin/python3.5
  -rwxr-xr-x 1 root root 4.3M Nov 17  2016 /mnt/usr/bin/python3.5m
  lrwxrwxrwx 1 root root   10 Apr  2  2017 /mnt/usr/bin/python3m -> python3.5m 

• Ran

  Code: Select all

   ls -lh /mnt/etc/alternatives/|grep python 

  to get :

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  lrwxrwxrwx 1 root root  18 Nov 10 20:25 python3 -> /usr/bin/python3.6
  lrwxrwxrwx 1 root root  28 Jul  6 23:50 wx.pth -> /usr/lib/wx/python/wx3.0.pth 

  
  as a result.

Is that all of it? Would that fix the problem or there is another step(s) after this? I will restart my computer without the live USB drive and report whether the problem is solved or not, if this was supposed to solve it.

Thanks!

[shesanp]

Update: The problem remains. Still no access to the terminal or most of the desktop environment.

Help!!!

[WharfRat]

That wasn't supposed to fix anything as all you were doing is listing files to provide more information.

That helped a lot as this link lrwxrwxrwx 1 root root 25 Nov 10 20:25 /mnt/usr/bin/python3 -> /etc/alternatives/python3 needs to be fixed.

Boot back up to the live media and sudo mount -t ext4 -v /dev/sda2 /mnt

Then the following one line at a time

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sudo -i
cd /mnt/usr/bin/
rm -v ../../etc/alternatives/python3
rm -v ../../etc/alternatives/wx.pth
rm -v python3
ln -s python3.5 python3
exit
exit

Reboot from the menu

[shesanp]

worked like a charm. Thank You very much!

I was wondering if you could give a succinct explanation of what the problem was, and how it was resolved. I get that in the first part we were trying to remove the new python installation so that the older one could be used for the system functions and tools that it was required for.

However, why didn't just uninstalling the package work? Were there just residual files following the uninstall that needed to be removed as well?

[WharfRat]

worked like a charm. Thank You very much!

I was wondering if you could give a succinct explanation of what the problem was, and how it was resolved. I get that in the first part we were trying to remove the new python installation so that the older one could be used for the system functions and tools that it was required for.

However, why didn't just uninstalling the package work? Were there just residual files following the uninstall that needed to be removed as well?

Well I was hoping that purging the python package would readjust those alternative links, but apparently it didn't

Instead it left the python3 -> /etc/alternatives/python3 link dangling.

To understand the concept of alternatives, it points to a substitute file - for instance unrar; If you list unrar you get

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[bill@vb] /etc/alternatives $ ls -lh /usr/bin/unrar
lrwxrwxrwx 1 root root 23 Jul 14 00:35 /usr/bin/unrar -> /etc/alternatives/unrar*

Now if you list /etc/alternatives/unrar you get

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[bill@vb] /etc/alternatives $ ls -lh /etc/alternatives/unrar
lrwxrwxrwx 1 root root 22 Jul 14 00:35 /etc/alternatives/unrar -> /usr/bin/unrar-nonfree*

So any application that uses unrar would just be redirected to /usr/bin/unrar-nonfree

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[bill@vb] /etc/alternatives $ ls -lh /usr/bin/unrar-nonfree
-rwxr-xr-x 1 root root 285K Aug 10  2015 /usr/bin/unrar-nonfree*

In the case of python, update-alternatives was supposed to allow for two python3 versions from the links in /etc/alternatives.

However I don't know how that was supposed to work if the newer python borked the system when it was in effect

You can man update-alternatives for an in-depth explanation