Original bug ID: 6416
Reporter: dwang
Assigned to: @Octachron
Status: resolved (set by @Octachron on 2018-06-26T20:19:28Z)
Resolution: fixed
Priority: normal
Severity: minor
Platform: x86 64-bit
OS: Linux CentOS 6
OS Version: 2.6.32-358.23.2.
Version: 4.01.0
Fixed in version: 4.08.0+dev/beta1/beta2
Category: typing
Related to: #4791
Monitored by: @gasche

Bug description

Compile this code:

module M = struct
type t = A
module M : sig
val f : t -> unit
end = struct
type t = B
let f B = ()
end
end

The error is

Values do not match: val f : t -> unit is not included in val f : t -> unit
Line 4, characters 4-21: Expected declaration
Line 7, characters 8-9: Actual declaration

I would prefer the error to be more explicit that there are two
different types here both named 't'.

Steps to reproduce

Compile this code:

module M = struct
type t = A
module M : sig
val f : t -> unit
end = struct
type t = B
let f B = ()
end
end