[BUG] SessionEnd hook cancelled with "Request interrupted by user" on Ctrl+C in Version 2.1.72

Preflight Checklist

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

What's Wrong?

SessionEnd hook is cancelled with "Hook cancelled.[Request interrupted by user]" when the Claude Code session is terminated via Ctrl+C (user interrupt). The hook process is killed before it can execute any cleanup logic.

This is a regression — prior versions ran the SessionEnd hook to completion regardless of the session exit path.

What Should Happen?

SessionEnd should always run to completion regardless of how the session exits (normal /exit, Ctrl+C). The contract of a teardown hook is guaranteed execution — cancelling it on interrupt makes it unreliable.

Error Messages/Logs

SessionEnd hook [command] failed: Hook cancelled.[Request interrupted by user]

Steps to Reproduce

1. Configure a SessionStart async hook that spawns a long-lived background, paired with a synchronous SessionEnd hook to stop it:

{
"hooks": {
"SessionStart": [{
"hooks": [{
"type": "command",
"command": "my-start-script"
}]
}],
"SessionEnd": [{
"hooks": [{
"type": "command",
"command": "my-stop-script"
}]
}]
}
}

1. Start a Claude Code session
2. Press Ctrl+C to interrupt the session
3. SessionEnd hook fires but is immediately cancelled before reading stdin

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.71

Claude Code Version

2.1.72

Platform

AWS Bedrock

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

The hook is cancelled before any user code runs, so there is no way to detect or recover from this within the hook itself — there is currently no workaround.

Impact: any hook relying on SessionEnd is broken on user interrupt.