Closed
Description
Minimized code
import cats.syntax.all._
trait AAA[T]
object Test {
implicit def aaaShow[T](implicit showT: cats.Show[T]): cats.Show[AAA[T]] = ???
("Enforcing union type": Int | Unit) //This will give a Type Mismatch Error
}My build.sbt:
libraryDependencies += ("org.typelevel" %% "cats-core" % "2.2.0-M1").withDottyCompat(scalaVersion.value)
scalaVersion := "0.23.0-RC1"
https://github.com/FabioPinheiro/cats-money/tree/dotty-working-hard
Output
Expect the Type Mismatch Error almost immediately.
Expectation
The compilation should not take more than a few seconds!
If we replace the implicit def (that is a valid scala2 code) with:
given aaaShow[T](using cats.Show[T]) as cats.Show[AAA[T]] = ???
The compilation takes around 45 seconds (also very slow)
Also, there is not any to stop compilation
After a SIGINT the sbt prints: [warn] Canceling execution... but it never ends.
I don't know where to report this. I have to send a SIGKILL to sbt and to bloop/metals