t9127.scala:4: warning: possible missing interpolator: detected interpolated identifier `$s`
  val t = "$s"
          ^
t9127.scala:5: warning: possible missing interpolator: detected an interpolated expression
  val u = "a${s}b"
          ^
t9127.scala:6: warning: possible missing interpolator: detected interpolated identifier `$s`
  val v = "a$s b"
          ^
error: No warnings can be incurred under -Xfatal-warnings.
three warnings found
one error found