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jpsalm

Member

Registered: 2020-09-18

Posts: 7

ncurses 6.6 — input freeze in terminal applications after window focus

Not sure where to put this as I can't seem to find an ncurses issue tracker.

I had issues with stuck panes inside tmux after alt tabbing since upgrading ncurses.

Environment:
- ncurses 6.6-2
- tmux 3.6a
- tested with alacritty and gnome-terminal
- tested with fish shell 4.5 and 4.3.3 (issue is shell-independent)
- Linux kernel 6.19.6

Description:

Applications that use ncurses become unresponsive to all input after switching window focus away from and back to the terminal (
e.g. alt-tab). The freeze is intermittent — it typically takes a few seconds or several focus switches before it triggers. Once frozen, no
input reaches the application, including Ctrl+C. tmux prefix commands still work, and non-ncurses applications in the same tmux session are
unaffected.

Steps to reproduce:
1. Run tmux
2. Open nano (or vim) in a pane
3. Alt-tab away from the terminal window
4. Alt-tab back
5. Repeat a few times — within a few cycles, input to nano/vim stops working entirely

jpsalm

Member

Registered: 2020-09-18

Posts: 7

Re: ncurses 6.6 — input freeze in terminal applications after window focus

Oh, forgot to mention that downgrading ncurses and lib32 ncurses to 6.5-4 fixes the issue.

jpsalm

Member

Registered: 2020-09-18

Posts: 7

Re: ncurses 6.6 — input freeze in terminal applications after window focus

I think I spoke too soon.  Issue re-appeared, it was just harder to reproduce perhaps.

It looks like it was actually related to tmux's mouse mode, but I'm not sure about that yet.

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 74,654

Re: ncurses 6.6 — input freeze in terminal applications after window focus

after switching window focus away from and back to the terminal (e.g. alt-tab)

You're talking about alt+tab / focus cycling as features of your window manager?
Which one would that be? Gnome?

What do you consider an "non-ncurses application"?
Is bash affected?

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