[BUG] Claude Code hangs if you type too much into its "questions" tool

[walt93]

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report (please file separate reports for different bugs)
• I am using the latest version of Claude Code

What's Wrong?

I am in a session, and the model has used its "questions" tool to ask some questions.

I go to the last option where I can type something.

I have a lot to say here, and I type/paste several lines until all input to the terminal window stops.

The terminal window is completely locked. Ctrl-C does not interrupt. ESC does not interrupt. Closing the terminal appears to be the only way.

What Should Happen?

I should be able to type into this input buffer without completely locking the terminal. That's, like, bad or something. P0 data loss, right?

Error Messages/Logs

Steps to Reproduce

Do something that triggers Claude to ask a question using its tool.
Go to the "other" field and type a lot of text. Paste in a paragraph. You'll trigger it...

Claude Model

None

Is this a regression?

I don't know

Last Working Version

No response

Claude Code Version

2.0.35 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

No response

[github-actions]

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Found 3 possible duplicate issues:

1. [Bug] Clarifying questions freezes at character limit input #11144
2. [BUG] AskUserQuestion freezes the session on text box overflow #10203
3. [BUG] Question Clarification Tool Makes Claude Code Stuck sometimes #9961

This issue will be automatically closed as a duplicate in 3 days.

• If your issue is a duplicate, please close it and 👍 the existing issue instead
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🤖 Generated with Claude Code

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[walt93]

I started another instance of Claude Code and had it do some investigation. This is its report.

Bug Report Information for Claude Code Issue

Here's what I've discovered about the frozen terminal issue:

Environment Details

• Claude Code Version: 2.0.35
• Platform: Linux 5.15.0-112-generic (Ubuntu)
• Node Version: v20.19.0

Process Information

• Stuck Process PID: 2576994
• Parent Process: 2567966
• Terminal: pts/6
• Process State: Sl+ (Sleeping, foreground process group leader)
• Wait Channel: futex_wait_queue_me (waiting on a futex - likely waiting for user input)
• Runtime: Started at 20:50, has accumulated 35 seconds of CPU time

Issue Description

The Claude instance is stuck in a futex wait state after the user attempted to type a large amount of text into the "Other"
field of the AskUserQuestion tool's response dialog. The terminal is completely unresponsive to:

• Typing
• Ctrl+C
• ESC key

Technical Findings

1. Process is blocked on user input: The futex_wait_queue_me wait channel indicates the process is waiting for a
   synchronization primitive (likely related to the input handling)
2. File descriptors: The process has multiple pipes and the terminal (pts/6) attached, but appears to be deadlocked
3. No crash: The process is alive and sleeping, not crashed - it's waiting for something that will never come

Reproduction Context

• User was working in /home/ubuntu/management project
• Last activity before freeze: Attempting to enter text into the "Other" field of a question response
• The "Other" field apparently has issues handling large text input

Additional Notes from CLAUDE.md

The project documentation notes: "IntelliJ IDEA environment has issues with ESC key interruption" - this suggests there may
be known terminal/input handling issues in this environment.

Recommended Debug Info to Include

1. The process is stuck in a futex wait (synchronization primitive)
2. Entering large amounts of text in the "Other" field causes complete terminal freeze
3. No graceful interrupt mechanism works (Ctrl+C, ESC)
4. The process appears to be waiting for input completion that never resolves

Workaround: The only way to recover is likely to kill the process from another terminal using kill -9 2576994 or similar.

This appears to be a deadlock in the input handling code for the AskUserQuestion tool when processing large text inputs in
the "Other" field.

[vak]

persists in 2.0.36 (and previous versions).
CTRL-z isn't working as well

[lee-queueone]

I reported a duplicate issue that I closed in favour of this one.

I am using macOS, claude code 2.0.36

Seems to happen around the ~800 character limit for me (have been able to reproduce a few times).

Would be great to have at least a hard character limit before the crash - I tend to lose a lot of work if this happens.

[vak]

btw, it happened to me mostly in a tabbed phase of the plan-on mode.

Also, sometimes I notice a tiny increase of latency between a key is pressed and a character is popped up in console -- sorry, if it is not related.

[lee-queueone]

My experience is the same as @vak - the issue happens in the tabbed phase of plan mode.

[github-actions]

This issue has been inactive for 30 days. If the issue is still occurring, please comment to let us know. Otherwise, this issue will be automatically closed in 30 days for housekeeping purposes.