Commands in shell_command do not run as expected

[ksalman]

Step 1: Provide a summary of your problem

• For general technical questions, problems or feature requests related to the code in this repository file an issue.

Step 2: Provide tmuxp details

• Python version
  2.7.6

• system PATH
  /u/ksalman/.pyenv/plugins/pyenv-virtualenv/shims:/u/ksalman/.pyenv/shims:/u/ksalman/.pyenv/bin:/u/ksalman/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games:/u/qa/tools:/usr/X11R6/bin:/u/qa/lab/scripts:/u/ksalman/scripts

• tmux version
  tmux 2.7-rc

• tmuxp version
  tmuxp 1.5.1

• tmux path
  /usr/local/bin/tmux

• tmuxp path,
  /u/ksalman/.pyenv/shims/tmuxp

• libtmux version
  libtmux==0.8.1

• shell
  GNU bash, version 4.3.30(1)-release (i586-pc-linux-gnu)

• output of tmux list-sessions, tmux list-windows, tmux list-panes
  [ksalman@dalaran:~] $ tmux list-sessions
  0: 18 windows (created Thu Jun 7 14:41:45 2018) [105x53] (attached)
  smoot: 7 windows (created Tue Feb 26 10:14:18 2019) [129x42]

[ksalman@dalaran:~] $ tmux list-windows
0: bash- (2 panes) [105x53] [layout eb9a,105x53,0,0[105x26,0,0,0,105x26,0,27,937]] @0
1: openstack (2 panes) [105x53] [layout e033,105x53,0,0[105x21,0,0,2,105x31,0,22,3]] @1
2: ssh (2 panes) [105x53] [layout 7b0d,105x53,0,0{23x53,0,0,194,81x53,24,0,195}] @106
3: aptly (1 panes) [105x53] [layout 6f0b,105x53,0,0,232] @120
4: solaris-oak-vcs2960 (1 panes) [105x53] [layout 6f0e,105x53,0,0,273] @134
5: jiracurl (1 panes) [105x53] [layout 6f0f,105x53,0,0,445] @188
6: bash (3 panes) [105x53] [layout bfd2,105x53,0,0[105x21,0,0,448,105x31,0,22{28x31,0,22,459,76x31,29,22,460}]] @190
7: bash (2 panes) [105x53] [layout f507,105x53,0,0[105x21,0,0,487,105x31,0,22,488]] @203
8: bash (1 panes) [105x53] [layout 2f0d,105x53,0,0,514] @218
9: bash (3 panes) [105x53] [layout 1c1b,105x53,0,0{31x53,0,0,517,73x53,32,0[73x21,32,0,550,73x31,32,22,552]}] @219
10: emeril (3 panes) [105x53] [layout 6ecd,105x53,0,0[105x21,0,0,766,105x31,0,22{45x31,0,22,749,59x31,46,22,833}]] @279
11: bash (2 panes) [105x53] [layout a1a5,105x53,0,0{45x53,0,0,838,59x53,46,0,839}] @308
12: bash (1 panes) [105x53] [layout ef0b,105x53,0,0,850] @311
13: bash (1 panes) [105x53] [layout ef0d,105x53,0,0,852] @312
14: (1 panes) [105x53] [layout ef13,105x53,0,0,858] @314
15: bash (1 panes) [105x53] [layout d7b7,105x53,0,0,1023] @396
16: bash (1 panes) [105x53] [layout d7be,105x53,0,0,1049] @405
17: vi* (2 panes) [105x53] [layout 1fb2,105x53,0,0[105x26,0,0,1089,105x26,0,27,1109]] @423 (active)

[ksalman@dalaran:~] $ tmux list-panes
0: [105x26] [history 0/50000, 0 bytes] %1089
1: [105x26] [history 0/50000, 0 bytes] %1109 (active)

• output of tmux show-options -g, tmux show-window-options -g
  [ksalman@dalaran:~] $ tmux show-options -g
  activity-action other
  assume-paste-time 1
  base-index 0
  bell-action any
  default-command ""
  default-shell "/bin/bash"
  destroy-unattached off
  detach-on-destroy on
  display-panes-active-colour red
  display-panes-colour blue
  display-panes-time 1000
  display-time 750
  history-limit 50000
  key-table "root"
  lock-after-time 0
  lock-command "lock -np"
  message-command-style fg=yellow,bg=black
  message-style fg=black,bg=yellow
  mouse off
  prefix C-a
  prefix2 None
  renumber-windows on
  repeat-time 500
  set-titles off
  set-titles-string "#S:#I:#W - "#T" #{session_alerts}"
  silence-action other
  status on
  status-interval 15
  status-justify left
  status-keys vi
  status-left "[#S] "
  status-left-length 10
  status-left-style default
  status-position bottom
  status-right " "#{=21:pane_title}" %H:%M %d-%b-%y"
  status-right-length 40
  status-right-style default
  status-style fg=black,bg=green
  update-environment[0] "DISPLAY"
  update-environment[1] "SSH_ASKPASS"
  update-environment[2] "SSH_AUTH_SOCK"
  update-environment[3] "SSH_AGENT_PID"
  update-environment[4] "SSH_CONNECTION"
  update-environment[5] "WINDOWID"
  update-environment[6] "XAUTHORITY"
  visual-activity off
  visual-bell off
  visual-silence off
  word-separators " -_@"

[ksalman@dalaran:~] $ tmux show-window-options -g
aggressive-resize off
allow-rename off
alternate-screen on
automatic-rename on
automatic-rename-format "#{?pane_in_mode,[tmux],#{pane_current_command}}#{?pane_dead,[dead],}"
clock-mode-colour blue
clock-mode-style 24
force-height 0
force-width 0
main-pane-height 24
main-pane-width 80
mode-keys vi
mode-style fg=black,bg=yellow
monitor-activity off
monitor-bell on
monitor-silence 0
other-pane-height 0
other-pane-width 0
pane-active-border-style fg=green
pane-base-index 0
pane-border-format "#{?pane_active,#[reverse],}#{pane_index}#[default] "#{pane_title}""
pane-border-status off
pane-border-style default
remain-on-exit off
synchronize-panes off
window-active-style default
window-status-activity-style reverse
window-status-bell-style reverse
window-status-current-format "#I:#W#{?window_flags,#{window_flags}, }"
window-status-current-style bg=blue
window-status-format "#I:#W#{?window_flags,#{window_flags}, }"
window-status-last-style default
window-status-separator " "
window-status-style default
window-style default
wrap-search on
xterm-keys on

• output of tmuxp freeze <SESSION_NAME>

Step 3: Describe your environment

• Architecture: i686
• OS version: Debian 8.0

Step 4: Describe the problem:

Steps to reproduce:

Observed Results:

• What happened? This could be a description, log output, etc.
  Commands in shell_command appear to be running before the shell is initialized. When I load the config pasted below, I get this in the pane created:

 cd /var/log
 echo foo
[ksalman@dalaran:~] $  cd /var/ echo

Expected Results:

• What did you expect to happen?
  I would expect commands to run and the output would look like this:

[ksalman@dalaran:~] $ cd /var/log
[ksalman@dalaran:/var/log] $ echo foo
foo

Relevant Code:

session_name: test
windows:
- window_name: test
  panes:
     - shell_command:
         - cd /var/log
         - echo foo

[joseph-flinn]

@ksalman I did not try replicating your environment, but from a quick test on my setup (Python 3.9, tmuxp 1.7.0, tmux 3.0a), I get the expected output from the example session yaml that you attached. Are you still having an issue with this? (I know it has been a while since you have opened this issue, but didn't want to close it without resolution).

[markmuetz]

I saw a similar issue as above, where I found that the shell_commands were not being executed (and it appeared as if a tab key was being inserted after the first command - a tab complete listing was coming up - perhaps related?). The behaviour is consistent across multiple machines running a variety of (old-ish, 2.1-2.9) versions of tmux. I had seen similar problems with my own bash script for launching tmux sessions, where I fixed it by adding in a sleep 10 call. I noticed that recent versions of tmuxp has a similar sleep_before option (undocumented?). For me this fixes my problem:

session_name: test
windows:
- window_name: test
  panes:
     - shell_command:
         - cd /var/log
         - echo foo
         sleep_before: 0.5

N.B. I think this is applied on a per-pane basis. It would be good if you could do this per-window (or even per-session), although I'm not sure if this is currently possible. Currently, this causes quite a lengthy wait for tmux to start up.

[tony]

N.B. I think this is applied on a per-pane basis. It would be good if you could do this per-window (or even per-session), although I'm not sure if this is currently possible.

I think it would be fine if you made an issue for this. It sounds like a good idea

[piotr-dobrogost]

Fixing bugs by inserting random sleep is definitely not a good idea…

[tony]

@piotr-dobrogost What do you propose?

[piotr-dobrogost]

I'm not familiar with the internals of the project and can only say what many others would say; we should investigate the problem and find the reason for this race. If the reason is that shell is not initialized as suggested earlier it seems the solution is to find a way to wait for shell's initialization to be completed before running commands.

[markmuetz]

@piotr-dobrogost I agree in principle. Adding a sleep is definitely a workaround. It does work though. I am happy to investigate further or provide info on my tmux setup, but this does affect me on multiple computers. For me, and for the time being, adding in a short sleep is acceptable.

It seems like what is needed is either polling the shell to see if it accepting commands, or a callback that is triggered after the shell has been initialized. However, I don't know about the internals well enough (or the intersection between tmux/bash/tmuxp/libtmux) to know if either of these is possible.

[piotr-dobrogost]

Googling for tmux wait for shell brings this Tmux in bash script executing too fast. The title is probably not quite right, the answer (needlessly?) uses sleep but what is interesting is that they use tmux wait-for which maybe could be a better workaround than plain sleep.

[tony]

@piotr-dobrogost @markmeutz

tmuxp isn't in control of shell commands themselves finishing. that is why sleep exists.

there may be ways to do such a thing but having it done in a portable + simple fashion is another question.

• a smarter wait: we may be able to delay a command until pane output . Wait until <condition> to send command (blocking send command) #96

  we may be able to hook into a string match of libtmux.Pane.capture_pane() to see if a command completes

• tmux wait-for

  seems worth making an issue for in libtmux. It'd be perfect fit for a context manager.

  Look into tmux wait-for libtmux#366 (comment)

  i don't know yet whether it helps here though. it depends on the user

  The sleep that tmuxp does isn't a sending keys to sleep, it's time.sleeping in the workspace builder.

[tony]

It seems like what is needed is either polling the shell to see if it accepting commands, or a callback that is triggered after the shell has been initialized. However, I don't know about the internals well enough (or the intersection between tmux/bash/tmuxp/libtmux) to know if either of these is possible.

These may be possible in the future but would need to be organized into their own issues