Raised by Mimir.Pricing for a misconfigured pricing entry — the
:mimir, :pricing config table's, or a Mimir.Snapshot's own — rather
than any other ArgumentError a bug or a hostile environment might
raise from the same call. Mimir.Guard rescues only this exception and
halts instead of raising mid-run; calling Mimir.Pricing or
Mimir.Oracle directly still raises it.