“Must be connected to a terminal error” with scree

Question

I am using Linux containers with Proxmox 4. When I am connected on an Ubuntu 16.04 container with:

pct enter <id>

I run a script with screen and try to watch the process running with:

screen -x <processname>

I got the error:

Must be connected to a terminal error

When I connect with:

ssh -t <user>@<container_ip>

It works, I can attach the display to the screen.

How can I use screen -x when I am connected with pct enter ?

Answer 1

I found a solution that works for same case(https://www.svennd.be/screen-in-lxc-attach)

Execute this

script /dev/null

Then you can run screen, et voila

Answer 2

This is happening mostly because of the reason that you must have switched user to the current terminal user using the command sudo su or user changing command. You will need to own the shell on which you are working. You can do so by running this: script /dev/null.

Alternatively, You can restart the terminal session with the user(which was used when creating screen) and not coming to current user using switch user commands.

To know active screens : screen -list