Cannot log into Ubuntu 16.04 after installing Marionnet

Hi David,

the script shows the names of all files related to X server which it
modifies. If you don't remember exactly the message it displayed, you
have to try several possibilities to restore a file content that doesn't
trouble the graphical login. Probably your manager doesn't understand a
configuration that another manager or another version of the same
manager understands. So, connecting you through a console (CTRL-Alt-F1),
you can try the following actions (with a textual editor like nano, vi,
emacs -nw, ...):

1) try to remove the line "xserver-allow-tcp=true" from
/etc/lightdm/lightdm.conf, if any, then try to reboot;
if the problem persists:

2) try to remove the line "DisallowTCP=false" from section "[security]
and/or
"Enable=true" from the section "[xdmcp]", if any, from all files named:

/etc/gdm/custom.conf
/etc/gdm?/custom.conf
/etc/gdm?/daemon.conf

Hope this helps.

Regards,

Jean-Vincent Loddo

Le 12/07/2017 à 16:57, David C. Mueller a écrit :
> New question #647572 on marionnet:
> https://answers.launchpad.net/marionnet/+question/647572
>
> I installed Marionnet using the marionnet_from-scratch script on my Ubuntu 16.04 computer. The installed script claimed it installed the program successfully but mentioned something about "restarting the x manager." After the install, I rebooted the computer. Now I cannot log back into Ubuntu. I get an error stating: "failed to start session". I made sure I was typing my password correctly. I had never seen this error before when logging into Ubuntu. What should I do now to resolve this issue?
>

Jean-Vincent Loddo:

Thanks for the suggestions. I will give them a try. Also, I was able to get logged into the Ubuntu GUI after logging into the Linux shell and running:

sudo apt-get install ubuntu-session
sudo apt-get install –reinstall ubuntu-session

Some updates installed once running this command. However, the Ubuntu GUI looks much different and is sluggish. Since the main function of this Ubuntu laptop is to work with Marionnet, this can be lived with. But when I try to launch Marionnet from the shell, I get the error:

Fatal error: exception Failure("The environment variable DISPLAY is not defined or empty, and Marionnet requires X. Bailing out . . .")

The following article suggests reconfiguring the X Server:

http://www.brianlinkletter.com/install-the-marionnet-network-simulator-on-debian-linux-6-0/

I may try that if your suggestions do not resolve the issue.

Thanks,

David Mueller

The effect of these commands

sudo apt-get install ubuntu-session
sudo apt-get install –reinstall ubuntu-session

is the same that I expected in my previous message. On the other hand,
the new problem, DISPLAY undefined, prevent the execution of graphical
programs. For instance, on my system, where marionnet seems well
installed ;-), I can observe otherwise:

$ unset DISPLAY

$ xterm
xterm: Xt error: Can't open display:
xterm: DISPLAY is not set

$ xeyes
Error: Can't open display:

So, you have just to fix the good value for the (very relevant) system
variable DISPLAY, putting a command like
DISPLAY=":0.0"
in your /etc/bashrc or /etc/profile or ~/.bashrc.

Jean-Vincent Loddo

Le 12/07/2017 à 20:33, David C. Mueller a écrit :
> Question #647572 on marionnet changed:
> https://answers.launchpad.net/marionnet/+question/647572
>
> Description changed to:
> I installed Marionnet using the marionnet_from-scratch script on my
> Ubuntu 16.04 computer. The installed script claimed it installed the
> program successfully but mentioned something about "restarting the x
> manager." After the install, I rebooted the computer. Now I cannot log
> back into Ubuntu. I get an error stating: "failed to start session". I
> made sure I was typing my password correctly. I had never seen this
> error before when logging into Ubuntu. What should I do now to resolve
> this issue?
>
> MORE INFO ABOUT THE ISSUE:
>
> I was able to get logged into the Ubuntu GUI after logging into the
> Linux shell and running:
>
> sudo apt-get install ubuntu-session
> sudo apt-get install –reinstall ubuntu-session
>
> Some updates installed once running this command. However, the Ubuntu
> GUI looks much different and is sluggish. Since the main function of
> this Ubuntu laptop is to work with Marionnet, this can be lived with.
> But when I try to launch Marionnet from the shell, I get the error:
>
> Fatal error: exception Failure("The environment variable DISPLAY is not
> defined or empty, and Marionnet requires X. Bailing out . . .")
>
> 1) Based on the following article, it seems I may need to reconfigure
> the X Server:
>
> http://www.brianlinkletter.com/install-the-marionnet-network-simulator-
> on-debian-linux-6-0/
>
> 2) I will also try the steps suggested by Jean-Vincent Loddo
>

Thanks for the additional info. I will try that out after I get more familiar with the shell text editor vim.

Is there another distro of Linux that it is easier to install Marionnet on than Ubuntu? Would Xbuntu be a good choice? I have some experience with Xbuntu.

I would also be happy trying another Linux distro that is not in the Ubuntu family if that will make installation easier.

My Ubuntu GUI looks very different and runs poorly after the Marionnet install. Some programs I had installed on Ubuntu before installing Marionnet have disappeared entirely.

Since the main function of the Linux machine will be to run Marionnet, I want to use a distro that works best with Marionnet.

David

This question was expired because it remained in the 'Open' state without activity for the last 15 days.