[BUG] Errors restoring session when a sidekick.nvim panel is saved to it

[jamesblckwell]

Describe the bug
It seems like the plugin is running into issues restoring sidekick.nvim terminal buffers for whatever reason. I have attempted to close the buffer using both it's filetype (in close_filetype_on_save) and using the pre_save_cmds hook, both with no success - when the plugin is auto-saving. If I manually save the session using :AutoSession save then it closes the buffer just fine - however the session still errors on startup with the same error.

P.S I use ToggleTerm to handle regular terminal buffers and these seem to be working just fine leading me to believe this is an issue with sidekick.nvim/auto-session in particular.

To Reproduce
Steps to reproduce the behavior:

1. Install folke/sidekick.nvim.
2. Open the sidekick_terminal buffer.
3. Save the session
4. Restore the session

Expected behavior
I would expect the session to start without an error!

Screenshots
Error:

AutoSession Config:

Sidekick Config (ommitted keys for brevity):

Checkhealth
Paste the contents of checkhealth auto-session here

auto-session:                                                               ✅

Setup ~
- ✅ OK setup() called

Lazy.nvim settings ~
- ✅ OK Lazy.nvim support is enabled
- ✅ OK auto-session is not lazy loaded

Config ~
- ✅ OK No config issues detected

Current Config ~
- {
    close_filetypes_on_save = { "sidekick_terminal" },
    pre_save_cmds = { <function 1> },
    suppressed_dirs = { "~/", "~/Projects", "~/Downloads", "/" }
  }

General Info ~
- Session directory: /home/james/.local/share/nvim/sessions/
- Current session: /home/james/.config/nvim
- Current session file: /home/james/.local/share/nvim/sessions/%2Fhome%2Fjames%2F%2Econfig%2Fnvim.vim
- Selected picker: telescope

Baseline (please complete the following information):

• Result of set sessionoptions?: sessionoptions=blank,buffers,curdir,folds,help,tabpages,winsize,winpos,terminal,localoptions
• OS. e.g uname -a: Linux amatsu 6.6.87.2-microsoft-standard-WSL2 #1 SMP PREEMPT_DYNAMIC Thu Jun 5 18:30:46 UTC 2025 x86_64 GNU/Linux
• Neovim version nvim --version: NVIM v0.11.5 Build type: RelWithDebInfo LuaJIT 2.1.1765228720 Run "nvim -V1 -v" for more info
• Link to config: https://github.com/jamesblckwell/neovim-config/tree/bug/auto-session-sidekick-error

Additional context
The full session file I'm attempting to restore is available here: https://gist.github.com/jamesblckwell/020b3824a0e8488b39148d462004bdfa

[cameronr]

I think the issue is that require('sidekick.cli').close() doesn't delete the buffer immediately / synchronously, so it's still open when the session is generated.

You can have auto-session close the buffer by adding this to your auto-session config:

      close_filetypes_on_save = { 'sidekick_terminal' },

[jamesblckwell]

Hi @cameronr - that's already in the config! 😉 Doesn't seem to work however.

[cameronr]

Oh whoops, I missed that you already had that in your config. It's strange that that's not working for you because it worked for me when testing.

If you can share your entire nvim config, I can take a look and figure out what's going on.

[jamesblckwell]

@cameronr - of course, my entire config is also in the original report!

[cameronr]

Oh jeez, I need to read the reports more closely. I'll take a look, thanks!

[cameronr]

I pulled down jamesblckwell/neovim-config@bug/auto-session-sidekick-error but I'm not able to reproduce the error.

With close_filetypes_on_save = { 'sidekick_terminal' },, it's correctly closing the sidekick buffer before saving the session. Without close_filetypes_on_save, I still don't get the error but I do get a new terminal window. It looks like you're on WSL so it's possible that's a factor.

To help debug, can you do the following:

1. can you let me know how you're opening the sidekick buffer (e.g. <leader>aa)? I want to make sure I'm following your steps.
2. Open nvim with a normal file and a sidekick buffer
3. run :AutoSession save
4. Post the contents of that session file to this issue
5. exit nvim
6. Check the session file to see if it's different in anyway to the one in step 3 (It shouldn't be, but just in case)

You said that running :AutoSession save closes the buffer (as it should). I want to make sure that's reflected in the session file created immediately after the save command.