godot: export doesn't work with enums from another script/class

neither of the following work, where g is set to autoload

export var type = g.BMW
export(g.Type) var type = g.BMW

gives error:

built-in:7 - Parse Error: invalid index 'BMW' in constant expression
modules/gdscript/gdscript.cpp:583 - Method/Function Failed, returning: ERR_PARSE_ERROR

this works tho’:

var type = g.BMW

See attached project godot-dbg.zip

edit although it seems that if you close&reopen the project (possibly the scene, didn’t try that one) the error disappears so you might have to recreate from scratch the simple project I attached.