What do we call the information provided about an error once it is detected?

The correct answer is error diagnostics. When an error occurs in a system or software application, error diagnostics refers to the information and details provided about the nature of the error. This can include descriptions of the error, possible causes, and sometimes suggestions for how to fix or handle the error. Error diagnostics are crucial for troubleshooting and resolving issues, as they help developers and users understand what went wrong and how to proceed to rectify the problem.

The concept of erroneous data does relate to mistakes or incorrect information within a dataset, but it does not encompass the broader context of the diagnostic process following an error occurrence. Final testing refers to the last stage of the testing process to ensure that the software meets all requirements before going live, while field typically relates to data structures or domains but does not pertain directly to the detection of errors. Thus, error diagnostics stands out as the most relevant term for the information provided about an error after it has been detected.