Most people trust a green checkmark in a CI pipeline. If every job is marked as successful, we usually believe that everything worked correctly. I was doing the same. Then I found a case where a completely green workflow was hiding an important problem.
While testing hafiza-kur across different platforms, my main goal wasn't just to see green checkmarks. I wanted to build a full list of what broke on which platform. I needed to see every single error, without stopping the pipeline at the first failure.
To do this, I added continue-on-error: true to the test steps. It was a conscious choice: let the tests run to the end on every platform, collect the raw logs, and check the results later.
Then came Windows with Python 3.11 and 3.13. The test t_y42 ran 58 test scenarios. It took 91 seconds on Py3.11 and 110 seconds on Py3.13 to finish. The heavy lifting was completely done and the assertions ran. Then came the final step: printing the summary of the results to the console.
Right on the first line of the summary loop, Python hit a character that the default Windows console couldn't encode. UnicodeEncodeError.
