Remixing extendable type


I have a type defined as below:

extendable entity type RiskScoreHistory mixes ScoreHeader, TimedDataHeader<RiskScore> schema name 'RSH'

I remix this type in my package as below:

remix extendable entity type RiskScoreHistory<T> {
  parent: !T

So in my package, I want to create a new type like this:

type FacilityRiskScoreHistory mixes RiskScoreHistory<Facility>

However, when I provision, I get the following error:

{fileUrl:"-type-FacilityRiskScoreHistory.c3typ",lineNum:-1,colNum:-1,severity:"ERROR",message:"Variable bindings do not match the number of variables on type RiskScoreHistory",code:"NOT_CLASSIFIED"}

I also tried this:

entity type FacilityRiskScoreHistory extends RiskScoreHistory<Facility> type key 'FACRSH'

I still get the same error.
Main goal is to make this a RiskScoreHistory with the parent field set to Facility.