The same error occurs for me. I am using following versions of programs/libraries.

tmuxp 1.4.2
libtmux 0.8.0
python 3.6.8
tmux 2.8

I have also checked with git master (@03de018) version of tmuxp, the problem still exist.

I too had this issue and I took the time to dig a bit deeper into it as I had one environment where I saw the expected (non-broken) behavior and another with the ValueError: Session requires a 'session_id' problem.

There is command that is ran via subprocess (I believe) which invokes tmux to provide some information in a tab delimited format for parsing. Here's a screenshot showing the command/syntax that is issued to tmux outlined in red:

This screenshot shows the output that is returned from that command (outlined in red) and as you can see it is not tab delimited.

The environment that was broken was a docker container, and as it turns out, I had been a bit lazy in its creation and skipped the locale generation part. After properly setting up all the locale and my shell's LANG environment variable to en_US.utf8, everything started working as expected.

Analyzing the output again in the debugger shows the properly formatted string.

TL;DR - Check your locale settings and shell LANG variable as the string libtmux is expecting to see when invoking tmux is improperly formatted.

@trodery Can you please post the output of locale command in bash. I have tested my locale and LANG variable and they all seem to be fine. Other softwares do not have any issue with my locale setting.

My locale is set to

LANG=en_IN
LANGUAGE=
LC_CTYPE="en_IN"
LC_NUMERIC=en_IN.UTF-8
LC_TIME=en_IN.UTF-8
LC_COLLATE="en_IN"
LC_MONETARY=en_IN.UTF-8
LC_MESSAGES="en_IN"
LC_PAPER=en_IN.UTF-8
LC_NAME="en_IN"
LC_ADDRESS="en_IN"
LC_TELEPHONE="en_IN"
LC_MEASUREMENT=en_IN.UTF-8
LC_IDENTIFICATION="en_IN"
LC_ALL=

Hence, I suspect that the tmuxp might not support any other English locale except en_US.UTF-8.

Here's the output prior to moving to an English locale:

LANG=
LANGUAGE=
LC_CTYPE="POSIX"
LC_NUMERIC="POSIX"
LC_TIME="POSIX"
LC_COLLATE="POSIX"
LC_MONETARY="POSIX"
LC_MESSAGES="POSIX"
LC_PAPER="POSIX"
LC_NAME="POSIX"
LC_ADDRESS="POSIX"
LC_TELEPHONE="POSIX"
LC_MEASUREMENT="POSIX"
LC_IDENTIFICATION="POSIX"
LC_ALL=

The only other problem I experienced was with click which demanded a UTF-8 locale.

I have this problem, but didn't used to. The only thing I know of that changed somewhat recently was tmux itself, which is now 2.9a.

I have the very same problem since last evening (after a system update)

@sica07 What's the output of the locale command in bash?

@mayanksuman If it possible to try doing LANG set to en_IN.UTF-8? Can you let me know the session name in unicode? (I guess just pasting it here would be sufficient). As well as python -V, tmux -V and tmuxp -V

Hence, I suspect that the tmuxp might not support any other English locale except en_US.UTF-8.

Potentially. I have a feeling it may be click or tmux wanting UTF-8.

http://click.palletsprojects.com/en/5.x/python3/#python-3-surrogate-handling

@trodery Can you let me know the session name being used ? As well as python -V, tmux -V and tmuxp -V?

@rosshadden @sica07 Can you let me know the output of locale, tmux -V, tmuxp -V and python -V?

@vn-ki Can you show your session yaml file, locale, python -V, tmux -V, tmuxp -V and the command you're using to load the file?

@tony Unfortunately that was so long ago that I don't even remember what I was using it for at the time. It is no longer being used. Python was 3.6 but that's all I remember.

@tony

$ locale
LANG=en_US.utf8
LANGUAGE=en_US.utf8
LC_CTYPE="en_US.utf8"
LC_NUMERIC="en_US.utf8"
LC_TIME="en_US.utf8"
LC_COLLATE="en_US.utf8"
LC_MONETARY="en_US.utf8"
LC_MESSAGES="en_US.utf8"
LC_PAPER="en_US.utf8"
LC_NAME="en_US.utf8"
LC_ADDRESS="en_US.utf8"
LC_TELEPHONE="en_US.utf8"
LC_MEASUREMENT="en_US.utf8"
LC_IDENTIFICATION="en_US.utf8"
LC_ALL=en_US.utf8

 $ python -V
Python 2.7.13

$ tmuxp -V
tmuxp 1.5.4

I ran into the same issue as the original bug report while using tmux 3.0a and tmuxp 1.5.4. Setting the following in ~/.bash_locale and then sourcing it at the end of my .bashrc file resolved the issue.

I have tmux installed as a compiled binary from the release page source, and tmuxp was installed via pip3, using Python 3.5.2.

## Use UTF-8 everywhere                                        
export LANG=en_US.utf8                                         
export LANGUAGE=en_US.utf8                                     
export LC_CTYPE="en_US.utf8"                                   
export LC_NUMERIC="en_US.utf8"                                 
export LC_TIME="en_US.utf8"                                    
export LC_COLLATE="en_US.utf8"                                 
export LC_MONETARY="en_US.utf8"
export LC_MESSAGES="en_US.utf8"
export LC_PAPER="en_US.utf8"                                   
export LC_NAME="en_US.utf8"                                    
export LC_ADDRESS="en_US.utf8"                                 
export LC_TELEPHONE="en_US.utf8"
export LC_MEASUREMENT="en_US.utf8"
export LC_IDENTIFICATION="en_US.utf8"
export LC_ALL=en_US.utf8

I know I have some locale issues when running tmuxp from Nixpkgs on Ubuntu, but still think this issue should not happen.

Here is how it can be reproduced (by setting LC_ALL=C):

$ cat test.yaml 
session_name: issue-405
windows:
- panes:
    - echo did it load properly or die with a python traceback?

$ LC_ALL=C tmuxp load ./test.yaml
[...]
ValueError: Session requires a `session_id`

Hi, I'm having the same problem.

• MacOS 10.15.7
• iTerm2 3.3.12
• tmux 3.1c
• tmuxp 1.6.2
• zsh 5.8 (x86_64-apple-darwin19.3.0)
• Python 3.8.6

locale

LANG="en_US.utf8"
LC_COLLATE="C"
LC_CTYPE="C"
LC_MESSAGES="C"
LC_MONETARY="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_ALL="C"

env | grep "^LC"

LC_TERMINAL_VERSION=3.3.12
LC_CTYPE=en_US.utf8
LC_TERMINAL=iTerm2
LC_ALL=en_US.utf8
LC_NUMERIC=en_US.utf8
LC_TIME=en_US.utf8
LC_COLLATE=en_US.utf8
LC_MONETARY=en_US.utf8
LC_MESSAGES=en_US.utf8
LC_PAPER=en_US.utf8
LC_NAME=en_US.utf8
LC_ADDRESS=en_US.utf8
LC_TELEPHONE=en_US.utf8
LC_MEASUREMENT=en_US.utf8
LC_IDENTIFICATION=en_US.utf8

env | grep "^LANG"

LANG=en_US.utf8
LANGUAGE=en_US.utf8

Here's a screencast of what is happening:

And here's the code of my script:

from libtmux import Server

if __name__ == '__main__':
    server = Server()
    if server.has_session("kubernetes-cluster-test"):
        session = server.attach_session("kubernetes-cluster-test")
    else:
        session = server.new_session("kubernetes-cluster-test", attach=True)
    try:
        window = session.select_window("kubernetes-cluster-test")
    except:
        window = session.new_window("kubernetes-cluster-test", attach=True)
    print(window.panes)

I also encountered this problem, and after debugging, I found that the method libtmux.server.Server._list_sessions uses \t to slice different columns, but in some environments the data returned by proc.stderr is not slice by \t.

The fix is to change the sliced character to something else, e.g. ||||

Same here:

Traceback (most recent call last):
File "/usr/bin/tmuxp", line 33, in
sys.exit(load_entry_point('tmuxp==1.9.4', 'console_scripts', 'tmuxp')())
File "/usr/lib/python3.10/site-packages/click/core.py", line 1128, in call
return self.main(*args, **kwargs)
File "/usr/lib/python3.10/site-packages/click/core.py", line 1053, in main
rv = self.invoke(ctx)
File "/usr/lib/python3.10/site-packages/click/core.py", line 1659, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/usr/lib/python3.10/site-packages/click/core.py", line 1395, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/usr/lib/python3.10/site-packages/click/core.py", line 754, in invoke
return __callback(*args, **kwargs)
File "/usr/lib/python3.10/site-packages/click/decorators.py", line 26, in new_func
return f(get_current_context(), *args, **kwargs)
File "/usr/lib/python3.10/site-packages/tmuxp/cli.py", line 1096, in command_load
load_workspace(config[-1], **tmux_options)
File "/usr/lib/python3.10/site-packages/tmuxp/cli.py", line 683, in load_workspace
if builder.session_exists(session_name) and not append:
File "/usr/lib/python3.10/site-packages/tmuxp/workspacebuilder.py", line 107, in session_exists
self.session = self.server.find_where({'session_name': session_name})
File "/usr/lib/python3.10/site-packages/libtmux/common.py", line 316, in find_where
return self.where(attrs)[0]
File "/usr/lib/python3.10/site-packages/libtmux/common.py", line 347, in where
return list(filter(by, self.children))
File "/usr/lib/python3.10/site-packages/libtmux/server.py", line 185, in sessions
return self.list_sessions()
File "/usr/lib/python3.10/site-packages/libtmux/server.py", line 180, in list_sessions
return [Session(server=self, **s) for s in self._sessions]
File "/usr/lib/python3.10/site-packages/libtmux/server.py", line 180, in
return [Session(server=self, **s) for s in self._sessions]
File "/usr/lib/python3.10/site-packages/libtmux/session.py", line 57, in init
raise ValueError('Session requires a session_id')
ValueError: Session requires a session_id

@grammoboy2 Can you also provide the configuration you're using and tmuxp debug-info

session_name: 3-panes
windows:

• window_name: dev window
  layout: main-vertical
  shell_command_before:
  • cd ~/
    panes:
  • shell_command:
    • cd /var/log
    • ls -al | grep .log
  • echo hello
  • echo hello

debug.txt

I also encountered this problem, and after debugging, I found that the method libtmux.server.Server._list_sessions uses \t to slice different columns, but in some environments the data returned by proc.stderr is not slice by \t.

The fix is to change the sliced character to something else, e.g. ||||

If you use the prerelease version of tmuxp and libtmux, does passing env LIBTMUX_TMUX_FORMAT_SEPARATOR="|||" tmuxp load [session] work?

pip install --user --upgrade --pre tmuxp libtmux

@grammoboy2 Thank you

Output of locale, env | grep "^LC", env | grep "^LANG"

$ locale
LANG=C
LC_CTYPE="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_COLLATE="C"
LC_MONETARY="C"
LC_MESSAGES="C"
LC_PAPER="C"
LC_NAME="C"
LC_ADDRESS="C"
LC_TELEPHONE="C"
LC_MEASUREMENT="C"
LC_IDENTIFICATION="C"
LC_ALL=

$ env | grep "^LC"
no output

$ env | grep "^LANG"
LANG=C

@grammoboy2 Does setting this work? #405 (comment)

That works, this works too:

$ unset LANG
$ source /etc/profile.d/locale.sh

Note that the session still seems to start when giving that session_id error, cause when I start it after I did the locale thing, it ask to attach to a running session.

This works in st-term, but in lxterminal, I get strange border characters

lxterminal