[BUG] output of awsAuthRefresh not shown to user

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?

Using Amazon Bedrock, the stdout (or stderr) of the awsAuthRefresh command is not shown to the user. However, the output is seen in .claude/debug/latest logfile. All the user sees is claude waiting, until it eventually times out.

What Should Happen?

Claude should show the output of the command specified in awsAuthRefresh.

Error Messages/Logs

Steps to Reproduce

1. write a dummy script that just echoes something to stdout (e.g. echo "hello"; sleep 10).
2. in settings.json set "CLAUDE_CODE_USE_BEDROCK": "1" and set authAwsRefresh to this script
3. run claude and you should see 'hello' in the debug log, but not in the claude cli.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.0.76

Claude Code Version

2.1.6

Platform

AWS Bedrock

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

Note that in version 2.0.76, the output of the awsRefreshAuth command is not shown in the debug log.