Original bug ID: 7928
Reporter: @stedolan
Assigned to: @lpw25
Status: resolved (set by @gasche on 2019-02-20T21:22:25Z)
Resolution: duplicate
Priority: normal
Severity: minor
Version: 4.08.0+dev/beta1/beta2
Category: middle end (typedtree to clambda)
Duplicate of: #7920
Monitored by: @nojb

Bug description

The following program (shortened from lm_parser.ml in omake) causes ocamlopt to fail with an index out of bounds error:

module type A = sig type t end
module type Int = A with type t = int
module I : Int = struct type t = int end
module A : sig module X : Int end = struct module X = I end

The failure occurs on both 4.08 and trunk, but only with ocamlopt and not ocamlc. The backtrace is:

Fatal error: exception Invalid_argument("index out of bounds")
Raised by primitive operation at file "bytecomp/translmod.ml", line 895, characters 46-55
Called from file "list.ml", line 92, characters 20-23
Called from file "bytecomp/translmod.ml", line 991, characters 36-54
Called from file "bytecomp/translmod.ml", line 1012, characters 27-112
Called from file "bytecomp/translmod.ml", line 1190, characters 4-69
Called from file "bytecomp/translobj.ml", line 131, characters 13-18
Called from file "bytecomp/translmod.ml", line 1264, characters 18-65
Called from file "utils/misc.ml", line 31, characters 8-15
Re-raised at file "utils/misc.ml", line 45, characters 40-48
Called from file "driver/optcompile.ml", line 66, characters 2-94
Called from file "driver/optcompile.ml", line 66, characters 2-162
Called from file "utils/misc.ml", line 31, characters 8-15
Re-raised at file "utils/misc.ml", line 45, characters 40-48
Called from file "driver/compile_common.ml", line 124, characters 6-68
Called from file "utils/misc.ml", line 31, characters 8-15
Re-raised at file "utils/misc.ml", line 45, characters 40-48
Called from file "utils/misc.ml", line 31, characters 8-15
Re-raised at file "utils/misc.ml", line 45, characters 40-48
Called from file "driver/compenv.ml", line 597, characters 6-59
Called from file "list.ml", line 110, characters 12-15
Called from file "driver/compenv.ml", line 673, characters 2-61
Called from file "driver/optmain.ml", line 267, characters 6-163
Re-raised at file "parsing/location.ml", line 904, characters 22-25
Called from file "driver/optmain.ml", line 333, characters 6-37
Called from file "driver/optmain.ml", line 337, characters 2-9