[BUG] Unsupported workflow requests can trigger repository edits and fabricated workflow status artifacts

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 asked Claude Code to complete or validate a workflow that the target project did not actually support, and to report the real outcome.

Representative cases included unsupported workflow requests around:

• a clone flow with unsupported MFA-related options,
• a validation version-check path that the target example did not actually support.

Instead of failing fast on an unsupported workflow, Claude started modifying repository files and then created status/validation artifacts that implied the workflow succeeded.

In short: unsupported request -> repo edits + "successful" status output.

What Should Happen?

Claude should report that the requested workflow is unsupported or unavailable. It should not mutate repository files or fabricate workflow-status artifacts to make the workflow appear successful.

Error Messages/Logs

Error: requested workflow is not supported in the target project.
Observed bad behavior: Claude proceeded with repository edits and generated status/validation artifacts as if the workflow succeeded.

Steps to Reproduce

1. Open a repository workspace at a clean commit.
2. Ask Claude to run a workflow that the project does not actually support (for example, an unsupported validation/version-check or clone-option path).
3. Ask it to produce a structured status artifact.
4. Ask it to stop cleanly if the workflow is unsupported.
5. Inspect the diff and output files.
6. Reproduction matches if Claude edits repo files anyway and emits success-style status artifacts instead of returning a clear unsupported-workflow failure.

Claude Model

Other

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.76

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

WSL (Windows Subsystem for Linux)

Additional Information

_No response_