Type checking error in presence of layout annotation

Type checker refuses to unify type in presence of layout annotations.

For instance if we compile this contract:

type my_record is
[@layout:comb]
record [
 field1 : int;
 field2 : nat;
]

//declaring the function that returns the sender’s balance
function get_balance (const entry : option (int)) : my_record is 
   case entry of [
     None -> (failwith ("ba bla"): record[field1: int ; field2 : nat])
   | Some (_o) -> record [field1 = 1 ; field2 = 0n]
   ]

we have the following error message:

File "test.pligo", line 11, characters 13-70:

Invalid type(s).
Expected: "my_record", but got: "record[field1 -> int , field2 -> nat]"

Then if we remove the annotation the compilation does not raise anymore this type error.