According to https://github.com/mongodb/mongo/wiki/The-%22failCommand%22-fail-point, the errorLabels option was introduced in 4.3.1 by SERVER-43941 and never backported. The option currently used in one UTF test in poc-retryable-writes.yml but the runOnRequirements permit that test to run on 4.0+ servers. The fact that the test passes suggests that configureFailPoint does not strictly validate data options like arguments for other server commands and may be ignoring unsupported values.

In any event, we should document the option in the UTF spec. The test can likely remain as-is, since errorLabels may only be necessary to ensure the label is added for 4.4+ servers where drivers won't add the label on their own based on an error code.

This came up in mongodb/specifications#1024 for DRIVERS-1483.