Breaking on "Duplicate keys of type were found in a Dictionary"

vanvoorden · July 2, 2025, 11:12pm

Is it this one?

stdlib/public/core/NativeDictionary.swift

swift-6.1.2-RELEASE


      
          // This function has a highly visible name to make it stand out in stack traces.
          @usableFromInline
          @inline(never)
          @_unavailableInEmbedded
          internal func KEY_TYPE_OF_DICTIONARY_VIOLATES_HASHABLE_REQUIREMENTS(
            _ keyType: Any.Type
          ) -> Never {
            _assertionFailure(
              "Fatal error",
              """
              Duplicate keys of type '\(keyType)' were found in a Dictionary.
              This usually means either that the type violates Hashable's requirements, or
              that members of such a dictionary were mutated after insertion.
              """,
              flags: _fatalErrorFlags())
          }