.tmux: The user in the status bar is stuck at root

[aofei]

The problem

I just pulled the latest commit from the master branch. Then I found that if I execute any sudo-prefixed command (such as sudo whoami), the user in the status bar will remain root!, even if I've returned to a standard user.

My setup

$ uname -a
Linux as-server 5.8.7-arch1-1 #1 SMP PREEMPT Sat, 05 Sep 2020 12:31:32 +0000 x86_64 GNU/Linux

$ tmux -V
tmux 3.1b

$ ssh -V
OpenSSH_8.3p1, OpenSSL 1.1.1g  21 Apr 2020

[gpakosz]

Hello @aofei 👋

I can't reproduce the problem here:

$ uname -a
Linux mustafar 5.8.9-arch2-1 #1 SMP PREEMPT Sun, 13 Sep 2020 23:44:55 +0000 x86_64 GNU/Linux

$ tmux -V
tmux 3.1b

After having pulled master, did you reload the configuration?

Before reloading the configuration can you please do a thing or two?

• Can you please paste the output of
  $ tmux show -gv status-right
• In a pane where you're not root but the status bar still displays root!, can you please do
  $ cut -c3- ~/.tmux.conf | sh -sx _username

[aofei]

Yes, I reloaded the configuration (C-a + r) and the problem exists.

However, I just killed the tmux session and recreated a new one, then the problem disappeared. So it's not a bug.

Sorry for wasting your time. Next time I'll also remember to restart the session before giving a feedback. 😥

[gpakosz]

You shouldn't have to restart the session.

I'll investigate more on this issue.

[aofei]

Okay, I'll pay attention. If I encounter it again, I'll report back here.

[aofei]

Yes it happened again.

$ tmux show -gv status-right
#[fg=#080808,bg=#080808,none]#[fg=#8a8a8a,bg=#080808,none]#[fg=none]#[bg=none]#[none]#{?client_prefix,⌨ ,}#[fg=none]#[bg=none]#[none]#{?session_many_attached,👓 ,}#[fg=none]#[bg=none]#[none]#{?pane_synchronized,🔒,} #{?battery_status, #{battery_status},}#{?battery_bar, #{battery_bar},}#{?battery_percentage, #{battery_percentage},} #[fg=#8a8a8a,bg=#080808,none] %R #[fg=#8a8a8a,bg=#080808,none] %d %b #[fg=#d70000,bg=#080808,none]#[fg=#e4e4e4,bg=#d70000,none] #(cut -c3- ~/.tmux.conf | sh -s _username #{pane_tty} false #D)#[fg=none]#[bg=none]#[bold,blink]#{?#{==:#(cut -c3- ~/.tmux.conf | sh -s _username #{pane_tty} #D),root},!,}#[default]#[fg=#e4e4e4,bg=#d70000,none] #[fg=#e4e4e4,bg=#d70000,none]#[fg=#000000,bg=#e4e4e4,bold] #(cut -c3- ~/.tmux.conf | sh -s _hostname #{pane_tty} false #h #D)

and

$ cut -c3- ~/.tmux.conf | sh -sx _username                                                                                                                                
+ :
+ set -e
+ unset GREP_OPTIONS
+ export LC_NUMERIC=C
+ LC_NUMERIC=C
+ printf ''
+ sed -E s///
++ uname -s
+ _uname_s=Linux
+ command -v pkill
+ _username
++ tmux display -p '#{pane_tty}'
+ tty=/dev/pts/0
+ ssh_only=
++ _tty_info /dev/pts/0
++ tty=pts/0
++ case "$_uname_s" in
++ ps -t pts/0 -o user=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX -o pid= -o ppid= -o command=
++ awk '
        NR > 1 && ((/ssh/ && !/-W/) || !/ssh/) {
          user[$2] = $1; parent[$2] = $3; child[$3] = $2; pid=$2; $1 = $2 = $3 = ""; command[pid] = substr($0,4)
        }
        END {
          for (i in parent)
          {
            j = i
            while (parent[j])
              j = parent[j]

            if (!(i in child) && j != 1)
            {
              print i":"user[i]":"command[i]
              exit
            }
          }
        }
      '
+ tty_info='584228:aofei:ps -t pts/0 -o user=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX -o pid= -o ppid= -o command='
+ command='aofei:ps -t pts/0 -o user=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX -o pid= -o ppid= -o command='
+ command='ps -t pts/0 -o user=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX -o pid= -o ppid= -o command='
++ _ssh_or_mosh_args 'ps -t pts/0 -o user=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX -o pid= -o ppid= -o command='
++ case "$1" in
++ printf %s ''
+ ssh_or_mosh_args=
+ '[' -n '' ']'
+ _is_enabled ''
+ '[' x = xtrue ']'
+ '[' x = xyes ']'
+ '[' x = xenabled ']'
+ '[' x = x1 ']'
+ username='aofei:ps -t pts/0 -o user=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX -o pid= -o ppid= -o command='
+ username=aofei
+ printf '%s\n' aofei
aofei

and the screenshot

[gpakosz]

When it happens, does tmux refresh-client -S help?

[aofei]

tmux refresh-client -S helped.

Sorry I haven't caught how it's triggered yet. But once it's triggered, executing any sudo-prefixed command in that session will cause problems. Then I have to restart the session or execute tmux refresh-client -S.

[gpakosz]

Well there's necessarily a lag between when you're no more root and when tmux decides to refresh the status line

What's the value of your tmux_conf_theme_status_left and tmux_conf_theme_status_right variables?

[gpakosz]

Also, tmux I see you have the prefix indicator in tmux_conf_theme_status_right which means tmux should refresh the status line when you hit prefix

[aofei]

Both tmux_conf_theme_status_left and tmux_conf_theme_status_right are the default values ​​specified by this project.

In fact, it's not a lag. It'll always be stuck at root! in that panel, no matter what command I execute later (or switch between different windows or panels). Unless I close that panel and create a new one. But if I execute a sudo-prefixed command in the new panel, the problem will show up again.

[gpakosz]

Ok I will keep investigating.

From what you reported, the fact that cut -c3- ~/.tmux.conf | sh -s _username in a pane for which the problem exhibits returns the proper username seems to indicate the problem lies in tmux not refreshing the status line

[gpakosz]

To further investigate, when it happens can you please

1. Describe the sequence of commands you launched to make it stuck, ideally a minimal repro

2. Get the current pane TTY (the pane for which the status bar doesn't update)

   $ tmux display -p '#{pane_tty}'
   

3. Go to another pane, and use ps -t with the value returned by the previous command, e.g.

   $ ps -t <TTY> -o user=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX -o pid= -o ppid= -o command=
   

And paste the output?

[aofei]

Ok, I'll pay attention next time it happens.

[gpakosz]

BTW what's the output of

$ tmux show -gv status-inverval

[aofei]

$ tmux show -gv status-interval
10

[gpakosz]

Hey @aofei 👋

Any news?

[aofei]

It happened several times recently. Unfortunately, I still don't know what specific steps are causing it. It's really cunning... 😥

But anyway, I'll still pay attention to it.