3.4.1 Cannot infer that the implementation of the parent class in a trait is type equivalent

[Christewart]

Compiler version

3.4.1

Minimized code

This can be reproduced by running wallet/compile on this commit: Christewart/bitcoin-s-core@cbec2d9

Parent traits

trait TxCRUDComponent[DbEntryType <: TxDB] {
  self: CRUD[DbEntryType, DoubleSha256DigestBE] =>
}

trait TxDAO[DbEntryType <: TxDB] {
  abstract class TxTable[DbEntryType](
      tag: profile.api.Tag,
      schemaName: Option[String],
      tableName: String
  ) extends Table[DbEntryType](tag, schemaName, tableName) {
    def txIdBE: Rep[DoubleSha256DigestBE]
  }

  type DbTable = TxTable[DbEntryType]
  override val table: TableQuery[DbTable]
}

Subclass that is failing to compile

case class IncomingTransactionDAO() extends TxDAO[IncomingTransactionDb] {

  override val table: slick.lifted.TableQuery[
    IncomingTransactionDAO.this.IncomingTransactionTable] = {
    TableQuery[IncomingTransactionTable]
  }
  class IncomingTransactionTable(tag: Tag)
      extends TxTable[IncomingTransactionDb](
        tag,
        schemaName,
        "wallet_incoming_txs"
      )
}

Output

[error] -- [E164] Declaration Error: /Users/chris/dev/bitcoin-s/wallet/src/main/scala/org/bitcoins/wallet/models/IncomingTransactionDAO.scala:17:15                                                         
[error] 17 |  override val table: slick.lifted.TableQuery[                                                                                                                                                  
[error]    |               ^                                                                                                                                                                                
[error]    |error overriding value table in trait TxDAO of type slick.lifted.TableQuery[IncomingTransactionDAO.this.DbTable];                                                                               
[error]    |  value table of type slick.lifted.TableQuery[IncomingTransactionDAO.this.IncomingTransactionTable] has incompatible type                                                                       
[error]    |----------------------------------------------------------------------------                                                                                                                    
[error]    | Explanation (enabled by `-explain`)                                                                                                                                                            
[error]    |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -                                                                                                                     
[error]    | I tried to show that                                                                                                                                                                           
[error]    |   slick.lifted.TableQuery[IncomingTransactionDAO.this.IncomingTransactionTable]                                                                                                                
[error]    | conforms to                                                                                                                                                                                    
[error]    |   slick.lifted.TableQuery[IncomingTransactionDAO.this.DbTable]                                                                                                                                 
[error]    | but none of the attempts shown below succeeded:                                                                                                                                                
[error]    |                                                                                                                                                                                                
[error]    |   ==> slick.lifted.TableQuery[IncomingTransactionDAO.this.IncomingTransactionTable]  <:  slick.lifted.TableQuery[IncomingTransactionDAO.this.DbTable]                                          
[error]    |     ==> IncomingTransactionDAO.this.DbTable  <:  IncomingTransactionDAO.this.IncomingTransactionTable                                                                                          
[error]    |       ==> IncomingTransactionDAO.this.TxTable[   org.bitcoins.core.api.wallet.db.IncomingTransactionDb]  <:  IncomingTransactionDAO.this.IncomingTransactionTable  = false                     
[error]    |                                                                                                                                                                                                
[error]    | The tests were made under the empty constraint                                                                                                                                                 
[error]     ----------------------------------------------------------------------------                                                                

Expectation

This should compile I think since IncomingTransactionTable is a subclass of TxTable[IncomingTransactionDb] ?

[Gedochao]

@Christewart we'll need to minimise this outside of the repo. Can you help?