you should idup the array and it will be able to go through, normal arrays are default sharable (as they have a shared mutable indirection)
as is the compiler can rewrite the sending as
Variant[] variants = [ Variant("user"), Variant("hello1234") ] ;
tid.send(Command.LOGIN, variants);
and Variant[] fails the hasUnsharedAlias test
you can fix this by making the array shared or immutable (and receiving the appropriate one on the other side)