Visual Code Python debugging tool crashes when trying to access "Model" object attributes before optimization

Consider the following code to model the maximum independent set problem to solve the maximum clique using MIP and NetworkX:

```
import mip
import networkx

n = 2 ** 3
g = networkx.binomial_tree(n)
networkx.add_star(g, [i for i in range(n)])
g1 = networkx.complement(g)

model = mip.Model("Independent Set")
x = [model.add_var(var_type=mip.BINARY) for _ in range(len(g1.nodes))]
model.objective = mip.maximize(mip.xsum(x[i] for i in range(len(g1.nodes))))
for (i, j) in g1.edges:
model += x[i] + x[j] <= 1
model.optimize()
selected = [i for i in range(len(g1.nodes)) if x[i].x >= 0.99]
print(selected)
g2 = g.subgraph(selected)
```

If I try to access the `model` variables in the `watch` section, it gives he following message on terminal:
```
Information not available, model was not optimized yet.
```
And then, the debugger dies. I believe this is not what should happen, some help with this?