Re: latest iterm2 hangs since a few days

[Frederic Beuserie]

also, 

this takes some miliseconds and nothing freeze (25K lines)

tar -tf xxx.tar | wc -l 

this freeze for 10 seconds the ui and i cannot bring iterm terminal back by using the dock and ctrl-tab or anything

tar -tf xxx.tar

frédéric.

On Sat, May 2, 2026 at 1:15 PM Frederic Beuserie <fbeu...@gmail.com> wrote:

Hello,

i'm running latest iterm2 on a mac book air M4.

i only experience this behavior with iterm2 and everything else run normal

it happended first i think after my latest osx update a few weeks ago. i'm now running 26.4.1 (25E253)

the most obvious symptom is just open a terminal on local machine, 

and run a command that output like 200 ou 300 lines (ex: php -i).

it hangs 5 seconds, nothing respond, terminal doesn't refresh, turning ball and all.

same for a "docker compose build" that output a lot of lines.

even somtimes navigating the settings and closing a confirmation dialog freeze for a while.

any idea where to looks ?

thanks

[Frederic Beuserie]

[George Nachman]

Thanks for the detailed report. A sample taken while iTerm2 is frozen will tell us exactly what it's stuck on, which is the fastest way to make progress.

Since iTerm2 itself is the thing hanging, you'll need to capture the sample from another app — Terminal.app works well. Here's the easiest way:

1. Open Terminal.app (or any other terminal).

2. Reproduce the freeze in iTerm2 — for example, run tar -tf xxx.tar so the UI is hung with the spinning beachball.

3. While it's still frozen, switch to Terminal.app and run:

sample iTerm2 5 -file ~/Desktop/iterm2-sample.txt

3. That captures 5 seconds of stack traces.

4. Once it finishes, attach ~/Desktop/iterm2-sample.txt to a reply.

It would also help to know the iTerm2 version: please send the exact version from iTerm2 > About iTerm2 (e.g., 3.6.x or a beta build number). If you're not on the latest beta, it's worth trying that first. Go to Settings > General > Selection and set the update channel to “Latest Beta Test Release,” then check for updates.

The sample is the most important piece. Once I see where it's stuck I can almost certainly point at the cause.

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[Frederic Beuserie]

Hi,

attached:

iterm2-sample3.txt: sample just after hitting enter on tar command.

if it can helps, iterm2-sample4.txt: sample after validating the beta channel on the settings->general (also beachball for some seconds).

version from the about menu is: Build 3.6.10

after the latest beta, same problem.

feel free to ask if something can helps you.

frédéric

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[George Nachman]

The first sample was because getting the user shell was very slow for some reason. Perhaps a server had to be contacted and the network was slow. Commit f44b784380eae56327b9f1d690832907b1249f2c caches it so you only have to do the slow part once.

The second was a hang when closing settings. It should be fixed by commit 9df5b40f2bdc5cfd220de305a0004ac4f00bf7ef.

You can verify in tomorrow’s nightly build. And I plan to put out a beta today as well, so you can test on that if you prefer.

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[Frederic Beuserie]

thanks, 

i checked with iTerm2-3_7_20260506-nightly (not sure if he already got those commits), i'll wait for next one to confirm if fixes something or not.

but with today's one => no changes

i tried something very simple:

open native Terminal aside item2.

on each i run "find Documents/".

- Terminal: takes a few seconds from start to finish, display instantly file name, no hangs, just normal terminal output going on

- iterm2: instant beachball, hangs for minutes (actually never finished), and activity monitor showed me it as "not responding", only with memory footprint going up by a few MB after a few seconds, continously). it looks like something is actually still running, I even got a permission request for iterm2 to access some folders, but the UI responsiveness is completely gone for this process. i finished by killing it. tried 2 times, one after full reboot. same.

hopes it can gives you some clues.. if you need me to do anything usefull to help, please ask.

thanks.

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[Frederic Beuserie]

Hello, to confirm: 

- for the settings, looks ok => thanks

- all the other tests involving displaying a lot of data are still positives. beachball and UI hanging

frédéric.

[George Nachman]

Thanks for confirming the Settings fix. The flood-of-output hang is a different bug, and the most useful next step is another sample taken while it's actually happening. The first one was just the shell lookup at startup, so it didn't tell us anything about this case.

Could you do this:

1. In iTerm2, run something that reliably hangs the UI. find ~/Documents is a great repro since you can reproduce it on demand.

2. Switch to Terminal.app while iTerm2 is still beachballing and run:

sample iTerm2 10 -file ~/Desktop/iterm2-find-hang.txt

2. (10 seconds this time, since the hang is longer.)

3. Attach ~/Desktop/iterm2-find-hang.txt to a new issue (which you can create at https://iterm2.com/bugs)

A couple of things to try in parallel that may either fix it or narrow it down:

- Try a default profile. Create a new profile (Settings > Profiles > +), leave everything at defaults, and open a session with it. If find ~/Documents runs cleanly there, the cause is something  configured on your existing profile — most likely Triggers, Smart Selection rules, or Semantic History. If you've added regex Triggers, those are evaluated against every line of output and a bad regex can absolutely cause this.

- Try toggling the GPU renderer. Settings > Advanced > search for "GPU". Try flipping "Disable the GPU renderer" and reopen the window. macOS 26 changed Metal/CALayer behavior in ways that have caused output-volume regressions before.

- The TCC permission prompt is a real clue. When macOS asks for Documents access mid-find, the syscall blocks until you answer. If iTerm2 is touching paths it sees in output (which it normally only does on click for Semantic History), that would explain everything. The sample will show whether that's what's happening.

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[Frederic Beuserie]

Hello,

To share, i finally fixed my last problem: iterm stuck for a while everytime i output a few lines of text on my terminal output ..

and that was a faulty regex inside my profile triggers that went crazy after i made some changes in it a few weeks ago (and i completely forgot about it ...)

the changes was to run a specific command but that command was using an bash alias not available in this subshell context ... thus outputing itself a few lines of error and this subshell

was respawned in a loop consuming a lot of ressources (on top of the buggy regex i think that also consumed a lot)

 

thanks for your help. finally solved and i can enjoy (again) my swift iterm.

cheers.

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[George Nachman]

It’s supposed to post a macOS notification when a command failed, but maybe you have them disabled. I’ll see if there’s a better way to notify you when this happens.

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