No mapping for CQL Long to FHIR v4.3 Integer64 - throw exception

[baseTwo]

The following CQL failed when running with the PackagerCLI when uncommenting the two lines to test CQL Long.

library EchoCQLTypes version '1.0.0'
using FHIR version '4.0.1'
parameter inputBoolean Boolean
parameter inputInteger Integer
// parameter inputLong Long
parameter inputDecimal Decimal
parameter inputDate Date
parameter inputDateTime DateTime
parameter inputTime Time
parameter inputString String
parameter inputQuantity Quantity
parameter inputRatio Ratio
parameter inputCode Code
parameter inputConcept Concept
parameter inputAny Any
parameter inputIntervalDate Interval<Date>
parameter inputIntervalDateTime Interval<DateTime>
parameter inputIntervalQuantity Interval<Quantity>
parameter inputList List<String>
parameter inputTuple Tuple { name String, age Integer }
parameter inputPatient FHIR.Patient
parameter inputObservation FHIR.Observation
context Patient
define "EchoBoolean": inputBoolean
define "EchoInteger": inputInteger
// define "EchoLong": inputLong
define "EchoDecimal": inputDecimal
define "EchoDate": inputDate
define "EchoDateTime": inputDateTime
define "EchoTime": inputTime
define "EchoString": inputString
define "EchoQuantity": inputQuantity
define "EchoRatio": inputRatio
define "EchoCode": inputCode
define "EchoConcept": inputConcept
define "EchoAny": inputAny
define "EchoIntervalDate": inputIntervalDate
define "EchoIntervalDateTime": inputIntervalDateTime
define "EchoIntervalQuantity": inputIntervalQuantity
define "EchoList": inputList
define "EchoTuple": inputTuple
define "EchoPatient": inputPatient
define "EchoObservation": inputObservation

Exception details:

System.ArgumentException
  HResult=0x80070057
  Message=Unable to identify a valid FHIR type for this parameter. Arg_ParamName_Name
  Source=Hl7.Cql.Packaging
  StackTrace:
   at Hl7.Cql.Packaging.ResourcePackager.ElmParameterToFhir(ParameterDef elmParameter, CqlTypeToFhirTypeMapper typeCrosswalk) in C:\Dev\firely-cql-sdk\Cql\Cql.Packaging\ResourcePackager.cs:line 356

When trying to add the missing mapping in CqlTypeToFhirTypeMapper, there is no Integer64 to pick from in the .NET SDK. (see screenshot below)

Raised the issue to the .NET SDK team in a Slack conversation

[ewoutkramer]

There is no long in R4, so the lines should stay commented, or it must be mapped to another type!

[baseTwo]

While the cql website includes this mapping to Integer64/Long, this FHIR type doesn't exist until v5.

I will just throw an Exception with this detail