FunctionClauseError in Dialyxir.WarningHelpers.ordinal/1 with opaque MapSet type

[mbaertschi]

Description

When running Dialyzer via dialyxir, an unknown error occurs when a MapSet is passed as a function argument and dialyxir tries to format the warning.

Error

Unknown error occurred: %FunctionClauseError{module: Dialyxir.WarningHelpers, function: :ordinal, arity: 1, kind: nil, args: nil, clauses: nil}

Legacy Warning

lib/aadb/addresses/source/types/source_data.ex:147:68: The call 'Elixir.Aadb.Addresses.Source.Types.SourceData':build_properties('write',#{'__struct__':='Elixir.MapSet', 'map':='Elixir.MapSet':internal(_)}) contains an opaque term as 2nd argument when terms of different types are expected in these positions
________________________________________________________________________________
lib/aadb/addresses/source/types/source_data.ex:164:27:call_without_opaque
Function call without opaqueness type mismatch.

Call does not have expected term of type %MapSet{:map => MapSet.internal(_)} (with opaque subterms) in the 1st position.

MapSet.member?(
  _required :: %MapSet{
    :map =>
      {:set, non_neg_integer(), non_neg_integer(), pos_integer(), non_neg_integer(),
       non_neg_integer(), non_neg_integer(), tuple(), tuple()}
      | %{_ => []}
  },
  _name :: any()
)

Expected Behaviour

Dialyxir should format the call_without_opaque warning with the opaque MapSet type without crashing.

Actual Behaviour

Dialyxir.WarningHelpers.ordinal/1 raises a FunctionClauseError, suggesting it receives an unexpected argument (likely the ordinal position of the opaque term — 2 in the legacy warning — that doesn't match any clause).