The error maddening.dtype

internal: a check on MIME’s own construction, which no supported script should reach: a MIME defect, to report with the file the error names; or an error MIME raised with no code yet (error.uncoded), keeping its own class, to report so that it gets one.

On the refusal list: no test names this code, since no file under tests/ names it. A test may still raise it without naming it, and none asserts it: what its message and action say is read from the source below. The hook that records which codes a test raises has not landed, so until it does the list says names and never raises. The list (docs/ratchets/refusal_codes.txt) only shrinks.

MIME gives it where its code is passed by name, so its words are read where it is raised.

Reading an error and reaching its full traceback: reading an error. Every code: the index.