I am willing to author a PR for this:

An issue that I've been having lately with the auto_error_formatter is the only argument is the value of an error. It would greatly beneficial, for the purposes of automatic testing and machine readability, for the function to accept/render the name of the error as well.

There are at least three ways to do this in render and FillingParser:

• invoke the auto_error_formatter with the error value and name; which is not backwards compatible
• accept an alt_auto_error_formatter, which would be used instead of auto_error_formatter
• keep auto_error_formatter as-is, but use a new arg like auto_error_formatter_args, which would default to '["value"]but could be overridden with["name", "value"]; and use that to control what auto_error_formatterdoes. (it could also be a versioned identifier likeauto_error_formatter_version=1vsauto_error_formatter_version=2`)