compiletime.error with s-interpolator crashes at runtime

[travisbrown]

Minimized code

object Test {
  inline def foo: String = scala.compiletime.error(s"")

  def main(args: Array[String]): Unit = println(foo)  
}

Output

Compiles but throws an exception at runtime:

Exception in thread "main" scala.NotImplementedError: an implementation is missing
        at scala.Predef$.$qmark$qmark$qmark(Predef.scala:347)
        at Test$.main(Test.scala:4)
        at Test.main(Test.scala)

Expectation

In the original code println(foo) shouldn't compile (and doesn't if you remove the s from the definition of foo). If using s in the error string isn't allowed, I'd expect the compiler to tell me that instead of throwing an exception at runtime.

[nicolasstucki]

We are not emitting an error in the following branch
https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/typer/Inliner.scala#L573