Bound evaluation error with -O2 optimisation but not -O1

[Mommessc]

I've encountered a strange behaviour of Minizinc when changing optimisation levels.
The MWE code below works fine with -O1 optimisation level, but gives an evaluation error: cannot determine bounds with higher optimisation levels.
I am using Minizinc 2.8.3, and I tried with Chuffed and Gecode so the issue seems independent of the solver used.

The model:

array[int] of record(0..100: a, 0..100: b): array1 = [(a: 16, b: 2), (a:8, b: 1)];

int: n = 1;

var 0..200: foo;
var 1..2: bar;

array[int] of var 0..200: sol = [ foo - (10 div array1[bar].b) | t in 1..n];

solve satisfy;

and here is the full error output (personal paths to files were truncated):

test_error_bound:9.1-29
  in variable declaration for 'sol'
  in array comprehension expression
    with t = 1
  in binary '-' operator expression
  in array literal
  in binary 'div' operator expression
stdlib_math:176-3.178-53
  in if-then-else expression
  in call 'div_t'
stdlib_internal:1985-3.1988-54
  in let expression
stdlib_internal:1986.5-53
  in variable declaration for 'z'
  in call 'compute_div_bounds'
MiniZinc: evaluation error: cannot determine bounds

Also, I noticed that if I remove the a part of the array1 record then everything works fine.