new Thread(new Runnable { ... @tailrec ... }).start()

val t = new Thread(new Runnable { ... @tailrec ... })
t.start()

// CORRECT - complains about annotation
// "not found: type nosuchannotation"
// donothing has parens, returns unit, but not called
object Example1 {
  class Wrapper(x: AnyRef) {
    def donothing {}
  }

  new Wrapper(new AnyRef {
    @nosuchannotation def method() {}
  })
}

// CORRECT - complains about annotation
// "not found: type nosuchannotation"
// donothing doesn't have parens, returns unit, called without parens
object Example2 {
  class Wrapper(x: AnyRef) {
    def donothing {}
  }

  new Wrapper(new AnyRef {
    @nosuchannotation def method() {}
  }).donothing
}

// CORRECT - complains about annotation
// "not found: type nosuchannotation"
// donothing has parens, returns unit, called without parens
object Example3 {
  class Wrapper(x: AnyRef) {
    def donothing() {}
  }

  new Wrapper(new AnyRef {
    @nosuchannotation def method() {}
  }).donothing
}

// INCORRECT - compiles without complaint
// donothing has parens, returns unit, called with parens
object Example4 {
  class Wrapper(x: AnyRef) {
    def donothing() {}
  }

  new Wrapper(new AnyRef {
    @nosuchannotation def method() {}
  }).donothing()
}

// INCORRECT - compiles without complaint
// donothing has parens, returns int, called with parens
object Example5 {
  class Wrapper(x: AnyRef) {
    def donothing(): Int = 1
  }

  new Wrapper(new AnyRef {
    @nosuchannotation def method() {}
  }).donothing()
}