An error that a template raises while it renders.
kind names the Python exception that Jinja2 raises in the same case, in snake case: :template_error for raise_exception, :undefined_error for an operation on an undefined value, :type_error, :value_error, :security_error for a sandbox violation, and others. message is the message of the Python exception.
line is the line of the template where the error happened, and name is the name of that template, nil for a template that Otera.parse/2 made from a string. They follow the template traceback of Jinja2: an error in a macro gives the line in the macro.