Error during logging of root-level propagation

[IgnaceBleukx]

Hi,

I'm experiencing an error when trying to solve an UNSAT CPMpy model with proof-logging enabled.
The model contains a bunch of AllDifferent and Element constraints.
I attached it as a pickled CPMpy format, as it quite large to convert to "pumpkin-native" manually.

This code snippet should reproduce the error (with CPMpy installed from here: https://github.com/ConSol-Lab/cpmpy)

import cpmpy as cp

model = cp.Model.from_file("set_game.pickle")
# print the model as it will be given to Pumpkin
for c in cp.SolverLookup.get("pumpkin").transform(model.constraints):
    print("-", c)

# this triggers the crash
model.solve(solver="pumpkin", proof="proof")

I can also export the model to MiniZinc is that is more helpful, but of course I'm not sure whether it will trigger the same crash.

Kind regads,
Ignace

unsat_set_game.zip