Weird interaction between given opaque types, extension method and repl

[johnynek]

minimized code

package Repro     
                                      
opaque type Foo = Int                 
                                                     
object Foo {                                         
  def empty: Foo = 0                                 
}                                                         
                                               
given FooOps {                                 
  def (f: Foo) +(that: Int): Foo = f + that    
} 

This code compiles, but in the repl you see:

sbt:dotty-example-project> console

scala> import Repro.Foo

scala> Foo.empty
1 |Foo.empty
  |^^^
  |Not found: Foo

Note, if you remove the given FooOps { then it Foo.empty works. So, this is somehow an interaction with the FooOps.

expectation

I expect that if I can compile it, I can reference it.

This was on 0.18.1-RC1

[liufengyun]

The issue cannot be reproduced.