[BUG] Claude fakes the output of a command and then doubles down on it

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?

I was running into issues with uv after re-creating a docker container. Claude suggested the new issues might be because the version of uv wasn't pinned in the setup scripts and there was a regression in uv, so I tried pinning it and recreated the docker container. Claude didn't realize that I'd recreated the docker container so when the issue didn't go away, it _faked_ the output of running uv --version to show that I was still on 0.10.0 (when I was now on 0.10.2). I pointed out it was fake and Claude doubled down and insisted it had actually run the command

What Should Happen?

Claude should not fake command outputs

Error Messages/Logs

Steps to Reproduce

No idea

Claude Model

Opus 4.6

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.49 (Claude Code vscode extension version)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

VS Code integrated terminal

Additional Information

<img width="1199" height="864" alt="Image" src="https://github.com/user-attachments/assets/e6b40cfb-22ed-407e-8f27-5988fdf92e0f" />