# type t = A of { x : int; mutable y : int; }
# Characters 14-15:
  let f (A r) = r;;  (* -> escape *)
                ^
Error: This form is not allowed as the type of the inlined record could escape.
# val f : t -> int = <fun>
# val f : int -> t = <fun>
# val f : t -> t = <fun>
# Characters 14-15:
  let f () = A {a = 1};; (* customized error message *)
                ^
Error: The field a is not part of the record argument for the t.A constructor
# val f : unit -> t = <fun>
#   type _ t = A : { x : 'a; y : 'b; } -> 'a t
# val f : 'a t -> 'a t = <fun>
# val f : 'a t -> 'a t = <fun>
#               module M :
  sig
    type 'a t = A of { x : 'a; } | B : { u : 'b; } -> unit t
    exception Foo of { x : int; }
  end
#                           module N :
  sig
    type 'b t = 'b M.t = A of { x : 'b; } | B : { u : 'bla; } -> unit t
    exception Foo of { x : int; }
  end
#     module type S = sig exception A of { x : int; } end
#       Characters 65-74:
    module A = (val X.x)
               ^^^^^^^^^
Error: This expression creates fresh types.
       It is not allowed inside applicative functors.
#           Characters 61-62:
    exception A of {x : string}
              ^
Error: Multiple definition of the extension constructor name A.
       Names must be unique in a given structure or signature.
#         Characters 58-59:
    exception A of {x : string}
              ^
Error: Multiple definition of the extension constructor name A.
       Names must be unique in a given structure or signature.
#         module M1 : sig exception A of { x : int; } end
#         Characters 34-44:
    include M1
    ^^^^^^^^^^
Error: Multiple definition of the extension constructor name A.
       Names must be unique in a given structure or signature.
#         module type S1 = sig exception A of { x : int; } end
#         Characters 36-46:
    include S1
    ^^^^^^^^^^
Error: Multiple definition of the extension constructor name A.
       Names must be unique in a given structure or signature.
#       module M : sig exception A of { x : int; } end
#       module X1 : sig type t = .. end
#     module X2 : sig type t = .. end
#       Characters 62-63:
    type X2.t += A of {x: int}
                 ^
Error: Multiple definition of the extension constructor name A.
       Names must be unique in a given structure or signature.
#         type _ c = C : [ `A ] c
type t = T : { x : [< `A ] c; } -> t
# val f : t -> unit = <fun>
#