What is time travel debugging?

Time travel debugging allows you to record a program's execution and move both forwards and backwards through the code history to see exactly how a bug occurred.

Does this skill work on Windows?

Currently, the Undo time travel debugger and this skill are focused on Linux program execution and debugging.

How does this handle flaky tests?

The skill uses the record tool to capture the execution of a test until it fails, creating a deterministic recording that Claude can analyze regardless of how often the bug occurs.

Do I need to add print statements to my code?

No, one of the primary benefits of this skill is that it captures the full state of execution without requiring any code modifications or extra logging.

Can I use standard GDB commands with this skill?

While it provides similar power to GDB, you should use the specialized Undo MCP tools provided with this skill rather than running raw bash commands to ensure Claude can interpret the time-travel data.

Time Travel Debugging with Undo

Name: Time Travel Debugging with Undo
Author: undoio

byundoio

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Security & Testing

Debugs Linux programs by recording execution and traveling backwards through history to resolve intermittent failures and race conditions.

About

This skill integrates Undo's time travel debugging technology into Claude, enabling a revolutionary way to handle complex software defects. By recording program execution—including precise thread interleaving—it allows developers to capture flaky tests and non-deterministic bugs that are otherwise impossible to reproduce. Claude can then use this skill to step backwards from a crash or assertion to the exact point of failure, providing root cause analysis without the need for manual code instrumentation or repeated execution cycles.

Key Features

Seamless integration with Undo MCP debugging tools
Traceability for race conditions and concurrency issues
1 GitHub stars
Backwards execution and reverse stepping through code
Deterministic recording of Linux program execution
Automated capture of intermittent and flaky test failures

Use Cases

Debugging flaky CI/CD tests by capturing a recording of the failure for offline analysis.
Analyzing a crash by stepping back from the segmentation fault to see where memory was corrupted.
Troubleshooting a race condition that only occurs under specific load conditions.

About

Key Features

Seamless integration with Undo MCP debugging tools
Traceability for race conditions and concurrency issues
1 GitHub stars
Backwards execution and reverse stepping through code
Deterministic recording of Linux program execution
Automated capture of intermittent and flaky test failures

Use Cases

Debugging flaky CI/CD tests by capturing a recording of the failure for offline analysis.
Analyzing a crash by stepping back from the segmentation fault to see where memory was corrupted.
Troubleshooting a race condition that only occurs under specific load conditions.