diff --git a/content/copilot/tutorials/copilot-chat-cookbook/debug-errors/diagnose-test-failures.md b/content/copilot/tutorials/copilot-chat-cookbook/debug-errors/diagnose-test-failures.md
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@@ -0,0 +1,103 @@
+---
+title: Diagnosing test failures
+shortTitle: Diagnose test failures
+intro: '{% data variables.copilot.copilot_chat_short %} can help you understand why a test is failing and suggest how to fix it.'
+versions:
+  feature: copilot
+category:
+  - Debugging code
+  - Author and optimize with Copilot
+complexity:
+  - Intermediate
+octicon: bug
+topics:
+  - Copilot
+contentType: tutorials
+---
+
+{% data variables.copilot.copilot_chat_short %} can analyze test failures and help identify potential causes.
+
+## Example scenario: Tests passing locally but failing in CI
+
+Consider a scenario where you have a test that passes on your local machine but sometimes fails in CI. {% data variables.copilot.copilot_chat_short %} can help identify the reason for the failure.
+
+In this example, the code being tested defines a simple order service (`order.py`), and there's a corresponding test that checks if an order was created today (`test_order_service.py`).
+
+## Example prompt
+
+The prompt below provides {% data variables.product.prodname_copilot_short %} with the relevant code and test files (using `#file:`) and includes a copy/paste of the relevant excerpt from the CI failure.
+
+```copilot copy
+Please take a look at this CI failure message. The test passes locally, but intermittently fails in CI. Can you help me figure out if this looks like a code bug, environment issue, or a flaky test?
+
+Failure:
+
+___ TestOrderService.test_order_created_today ___
+>       assert order["created_date"] == date.today()
+E       AssertionError: assert datetime.date(2024, 1, 15) == datetime.date(2024, 1, 16)
+
+test_order_service.py:45: AssertionError
+
+#file:order.py
+#file:test_order_service.py
+
+```
+
+## Example response
+
+{% data reusables.copilot.example-prompts.response-is-an-example %}
+
+{% data variables.copilot.copilot_chat_short %} notices that the dates are exactly one day apart and identifies that this could be a **timezone** or **time-boundary** issue.
+
+The local machine and CI runner may be using different timezone settings or deriving `today` from different clocks (UTC vs. local time), so when the test runs near midnight, `date.today()` can return different dates in each environment.
+
+{% data variables.copilot.copilot_chat_short %} suggests treating the failure as test flakiness caused by environment/time assumptions (and not a logic bug), and fixing it by standardizing how `today` is computed across environments.
+
+## Example scenario 2: Intermittent test failures
+
+Consider a scenario where a test sometimes passes and sometimes fails on the same machine. {% data variables.copilot.copilot_chat_short %} can compare logs from passing and failing runs to help identify the cause.
+
+In this example, the code under test uses a background job in `order_service.py` to update an order's status asynchronously, and a test in `test_order_service.py` asserts that the final status is `"processed"`.
+
+## Example prompt
+
+The prompt below provides {% data variables.product.prodname_copilot_short %} with the failure message, the log excerpts from both a passing and failing run, and the relevant code files (using `#file:`).
+
+```copilot copy
+This test passes sometimes and fails sometimes. Can you compare the logs and help me figure out why?
+
+Failure message:
+
+>       assert order.status == "processed"
+E       AssertionError: assert "pending" == "processed"
+
+test_order_service.py:62: AssertionError
+
+Logs from a passing run:
+[DEBUG] Created order #1234
+[DEBUG] Background job started for order #1234
+[DEBUG] Background job completed (52ms)
+[DEBUG] Checking order status
+[DEBUG] Order #1234 status: processed
+
+Logs from the failing run:
+[DEBUG] Created order #1234
+[DEBUG] Background job started for order #1234
+[DEBUG] Checking order status
+[DEBUG] Order #1234 status: pending
+
+#file:order_service.py
+#file:test_order_service.py
+```
+
+## Example response
+
+{% data reusables.copilot.example-prompts.response-is-an-example %}
+
+{% data variables.copilot.copilot_chat_short %} compares the two logs and notices that in the passing run, the background job completed *before* the status check, while in the failing run, the status was checked while the job was still running. {% data variables.copilot.copilot_chat_short %} notes that this is a **race condition**, as the test doesn't wait for the background job to finish.
+
+{% data variables.copilot.copilot_chat_short %} suggests adding a mechanism to ensure the job completes before asserting, such as running the job synchronously, awaiting completion (for example, via a callback), or polling.
+
+## Further reading
+
+{% data reusables.copilot.example-prompts.further-reading-items %}
diff --git a/content/copilot/tutorials/copilot-chat-cookbook/debug-errors/index.md b/content/copilot/tutorials/copilot-chat-cookbook/debug-errors/index.md
index c0d4e517c746..225b447b755d 100644
--- a/content/copilot/tutorials/copilot-chat-cookbook/debug-errors/index.md
+++ b/content/copilot/tutorials/copilot-chat-cookbook/debug-errors/index.md
@@ -12,6 +12,6 @@ topics:
 children:
   - /debug-invalid-json
   - /handle-api-rate-limits
+  - /diagnose-test-failures
 contentType: tutorials
 ---
-