Mosh: iTerm2: irssi in tmux remote over mosh leaves artifacts

[ChrisBuchholz]

I'm running irssi inside tmux on a remote server which I connect to via mosh, but it keeps leaving artifacts around or, in other words - not update the whole buffer.

The most noticable and ever repeating mishappen is, the whole buffer, containing irssi, resonates static, and only the single last line keeps updating as new messages are posted to the current channel.

Here is a typescript of a terminal session where this happens: https://dl.dropbox.com/u/168187/irssiresonatesstatic

And here is screenshot of a irssi session: https://dl.dropbox.com/u/168187/first.png
And here it is where the last line has updated, but the rest of the buffer has not: https://dl.dropbox.com/u/168187/second.png

[keithw]

Does this happen with irssi directly inside mosh (no tmux)?

[keithw]

And could you please upgrade mosh-server and mosh-client to 1.2.3 and see if you still have the problem? The trace output indicates that mosh-server is version 1.1.3 or earlier.

[ChrisBuchholz]

Nope, it works perfectly if not using tmux. Thats good to know. Also, my package manager says I have 1.2.3 installed.

[keithw]

scootserv's mosh-server appears to be 1.1.3 or earlier, based on the "mosh-server: invalid option -- 'l'" in the typescript. If you run mosh-server on scootserv, what version number does it print out?

[ChrisBuchholz]

Damn, I didn't think about checking what was installed on my server. That is indeed 1.1.3. Seems thats the latest available in ubuntu's upstream repository.

[keithw]

Ubuntu doesn't update its software after the release, but 1.2.3 is available in the PPA (directions are on http://mosh.mit.edu). (sudo add-apt-repository ppa:keithw/mosh; sudo apt-get update; sudo apt-get install mosh)

1.2.2 is also available in the Ubuntu "backports" repository for Ubuntu 12.04 LTS.

If you still see the problem with 1.2.3, could you please provide a typescript recorded (1) inside the tmux (and outside irssi) (2) inside mosh (and outside tmux) and (3) outside mosh? With those three, we should be able to nail down whose bug this is and figure out a fix for you.

[HorizonXP]

I'd like to pipe in to say that I'm experiencing the same issue with irssi running in Ubuntu's byobu. I'm running mosh 1.2.3 on both sides of the connection. Let me know what additional info you need to debug this, and I'll be happy to help.

[keithw]

Hello @HorizonXP -- the same info as we asked for in https://github.com/keithw/mosh/issues/341#issuecomment-9756349 would be much appreciated. Except I am going to just guess that you are running gnome-terminal as your outer terminal, in which case you are probably seeing a bug in VTE (the outer terminal emulator). Are you able to replicate the problem using xterm?

[HorizonXP]

Hey @keithw, I'm able to replicate the same problem using xterm. Also, I'm actually using xfce4-terminal 0.4.8, not gnome-terminal, though they're likely fairly similar.

I'm unclear about which typescripts you need.

1) A typescript inside tmux, outside of irssi, of just a shell session? Connecting via ssh or mosh?
2) Inside mosh, outside tmux, and inside of irssi?
3) Outside mosh, outside tmux, and inside irsssi?

[keithw]

Yes, we want to see the input to tmux, the output of tmux, and the output of mosh. (Simultaneously.)

[HorizonXP]

Sorry for not replying to this. I'm sorry, I'm a bit noob-ish. I'm not sure what exactly you need me to do. Am I running the 'script' command? How exactyl? Locally or remotely?

[HorizonXP]

Ok, I think I have what you need. Let me know if they help.

http://dl.dropbox.com/u/50184433/typescript_ssh_no_tmux
http://dl.dropbox.com/u/50184433/typescript_ssh_yes_tmux
http://dl.dropbox.com/u/50184433/typescript_mosh_no_tmux
http://dl.dropbox.com/u/50184433/typescript_mosh_yes_tmux

[theeternalsw0rd]

For what it's worth, I had this problem in weechat inside tmux without mosh. What is $TERM inside of tmux? If it is not a screen variant, you may have issues with redraw in ncurses inside tmux. If you need $TERM other than a screen variant inside of tmux, try starting irssi with TERM=screen-256color irssi. I use the following function in my zshrc file for calling weechat appropriately.

function irc () {
™  if [[ $TMUX = '' ]]; then
        weechat-curses
    else
        TERM=screen-256color weechat-curses
    fi
}

Then I just call irc from the shell to start weechat.

[HorizonXP]

@eternalsword that completely solved my issue. Thank you so much for chiming in and pasting that little script.

[nyuszika7h]

@eternalsword @HorizonXP Instead of setting TERM when starting irssi or WeeChat, you could add this snippet to your ~/.tmux.conf:

set -g default-terminal "screen-256color"

For screen, you can add this to your ~/.screenrc:

term screen-256color

You'll also need to make sure your local TERM supports 256 colors (e.g. xterm-256color), although that's probably already the case, as the xterm + screen pair shouldn't cause issues.

You can use this snippet to check if your TERM supports 256 colors:

#!/bin/bash

echo "TERM is set to ${TERM}."
echo -n 'COLORTERM is '
[ -n "$COLORTERM" ] && echo "set to ${COLORTERM}." || echo 'not set.'
echo "Colors: $(tput colors)"