Weird message "incompatible interpolation method s"

[som-snytt]

reproduction steps

scala 2.13.8> def format(i: Int): String = s"${format("")}"
                                           ^
              error: type mismatch;
               found   : String("")
               required: Int; incompatible interpolation method s

problem

The error in the arg induces an obscure addendum which probably intends to say there is something wrong with the types.

The caret position is not clarifying.

Presumably no interpolator is compatible with erroneous arguments.

[som-snytt]

Scala 3 improves hygiene, cf scala/scala#9934