0004487: Unable to override a value in a module type with ocamlc.

(0005523)
garrigue (manager)
2010-05-28 05:37

Fixed by only keeping the last declaration in signatures.

(0005730)
ertai (developer)
2010-12-07 17:06

This issue is not completely resolved, the fix seems to work only on the first duplicate.

$ cat bug.ml
module M : sig
  val t : bool
  val f : bool
  val t : int
  val f : int
end = struct
  let t = 42
  let f = false
end

$ ocamlc -c bug.ml
File "bug.ml", line 6, characters 6-45:
Error: Signature mismatch:
       Modules do not match:
         sig val t : int val f : bool end
       is not included in
         sig val t : int val f : int end
       Values do not match: val f : bool is not included in val f : int

(0005734)
garrigue (manager)
2010-12-12 06:41

The problem did exist in an intermediate fix, but it is already corrected in 3.12.
Your exemple is incorrect: the signatures inferred by the compiler are correct,
and indeed they do not match, so it is correct to report an error here.

(0005737)
ertai (developer)
2010-12-13 10:57

Sorry I made a mistake when reducing the bug (from around 0006885:0014000 lines of code), here is the new input:

$ cat bug.ml
module type S = sig
  val t : bool
  val f : bool
end
module M : sig
  include S
  val t : int
  val f : int
end = struct
  let t = 0
  let f = 1
end

$ ocamlc -c bug.ml
File "bug.ml", line 9, characters 6-40:
Error: Signature mismatch:
       Modules do not match:
         sig val t : int val f : int end
       is not included in
         sig val f : bool val t : int val f : int end
       Values do not match: val f : int is not included in val f : bool

This is the same output in 3.12, and today's trunk version.

(0005740)
garrigue (manager)
2010-12-13 13:13

Sorry for the confusion: this problem is completely fixed only in the
3.12 _branch_, i.e. in the upcoming version 3.12.1.
The fix will be merged in trunk following the release.

Issue History
Date Modified	Username	Field	Change
2008-01-23 00:50	jm	New Issue
2008-02-19 15:19	doligez	Status	new => acknowledged
2010-04-30 17:23	doligez	Relationship added	related to 0005037
2010-05-27 17:01	xclerc	Relationship added	related to 0005061
2010-05-28 05:37	garrigue	Note Added: 0005523
2010-05-28 05:37	garrigue	Status	acknowledged => closed
2010-05-28 05:37	garrigue	Resolution	open => fixed
2010-05-28 05:37	garrigue	Fixed in Version	=> 3.12.0+dev
2010-12-07 17:06	ertai	Assigned To	=> garrigue
2010-12-07 17:06	ertai	Note Added: 0005730
2010-12-07 17:06	ertai	Status	closed => feedback
2010-12-07 17:06	ertai	Resolution	fixed => reopened
2010-12-12 06:41	garrigue	Note Added: 0005734
2010-12-12 06:41	garrigue	Status	feedback => resolved
2010-12-12 06:41	garrigue	Resolution	reopened => no change required
2010-12-13 10:57	ertai	Note Added: 0005737
2010-12-13 10:57	ertai	Status	resolved => feedback
2010-12-13 10:57	ertai	Resolution	no change required => reopened
2010-12-13 13:05	garrigue	Relationship added	duplicate of 0005164
2010-12-13 13:13	garrigue	Note Added: 0005740
2010-12-13 13:13	garrigue	Status	feedback => resolved
2010-12-13 13:13	garrigue	Fixed in Version	3.12.0+dev => 3.12.1+dev
2010-12-13 13:13	garrigue	Resolution	reopened => fixed
2012-03-24 15:01	xleroy	Status	resolved => closed
2017-02-23 16:36	doligez	Category	OCaml general => -OCaml general
2017-03-03 17:55	doligez	Category	-OCaml general => -(deprecated) general
2017-03-03 18:01	doligez	Category	-(deprecated) general => ~deprecated (was: OCaml general)
2017-03-06 17:04	doligez	Category	~deprecated (was: OCaml general) => ~DO NOT USE (was: OCaml general)

Notes
(0005523) garrigue (manager) 2010-05-28 05:37	Fixed by only keeping the last declaration in signatures.

(0005730) ertai (developer) 2010-12-07 17:06	This issue is not completely resolved, the fix seems to work only on the first duplicate. $ cat bug.ml module M : sig val t : bool val f : bool val t : int val f : int end = struct let t = 42 let f = false end $ ocamlc -c bug.ml File "bug.ml", line 6, characters 6-45: Error: Signature mismatch: Modules do not match: sig val t : int val f : bool end is not included in sig val t : int val f : int end Values do not match: val f : bool is not included in val f : int

(0005734) garrigue (manager) 2010-12-12 06:41	The problem did exist in an intermediate fix, but it is already corrected in 3.12. Your exemple is incorrect: the signatures inferred by the compiler are correct, and indeed they do not match, so it is correct to report an error here.

(0005737) ertai (developer) 2010-12-13 10:57	Sorry I made a mistake when reducing the bug (from around 0006885:0014000 lines of code), here is the new input: $ cat bug.ml module type S = sig val t : bool val f : bool end module M : sig include S val t : int val f : int end = struct let t = 0 let f = 1 end $ ocamlc -c bug.ml File "bug.ml", line 9, characters 6-40: Error: Signature mismatch: Modules do not match: sig val t : int val f : int end is not included in sig val f : bool val t : int val f : int end Values do not match: val f : int is not included in val f : bool This is the same output in 3.12, and today's trunk version.

(0005740) garrigue (manager) 2010-12-13 13:13	Sorry for the confusion: this problem is completely fixed only in the 3.12 _branch_, i.e. in the upcoming version 3.12.1. The fix will be merged in trunk following the release.