"duplicate access modifier public" when trying to use injection

[davidgiven]

Trying to set up a boilerplate file using HexInject, I find that trying to declare an injector container just produces a "duplicate access modifier public" error:

import hex.di.IInjectorContainer;

class MockClass implements IInjectorContainer {}

class ServerMain {
        static public function main() {
        }
}

--->

$ haxe -cpp .obj/server-temp -debug -lib hexinject -main ServerMain
/usr/share/haxe/std/haxe/macro/Expr.hx:818: characters 2-10 : Duplicate access modifier public
ServerMain.hx:5: lines 5-9 : Defined in this class
/usr/share/haxe/std/haxe/macro/Expr.hx:818: characters 2-10 : Previously defined here
ServerMain.hx:5: lines 5-9 : Defined in this class
$ haxe --version
4.0.5

Is there anything obvious I'm doing wrong here?