"Failed to revert changes" when clicking "undo" button

What version of Codex is running?

codex-cli 0.61.1-alpha.1

What subscription do you have?

Pro

Which model were you using?

gpt-5.1-codex (issue occurs regardless of model)

What platform is your computer?

Darwin 25.1.0 arm64 arm

What issue are you seeing?

When clicking the "undo" button after codex makes changes, I get a red toast message saying "Failed to revert changes". This issue occurs on all models, whether or not I am using a git repo, on all 3 of my computers, etc.

Note that this is the same as issue https://github.com/openai/codex/issues/2997, but that appeared to have gotten "resolved" despite many people commenting that they were still experiencing the issue.

What steps can reproduce the bug?

1. Have codex make any changes to a repo.
2. Click "undo" on the most recent change that codex makes.

What is the expected behavior?

Clicking the "undo" button reverts that change.

Additional information

<img width="231" height="47" alt="Image" src="https://github.com/user-attachments/assets/4fde84c9-48ee-4cf6-b501-4d189cae7786" />