Weights for compact connected Lie groups

Let ℓ be a prime. If G G is a compact connected Lie group, or a connected reductive algebraic group in characteristic different from ℓ , and ℓ is a good prime for G G , we show that the number of weights of the ℓ -fusion system of G G is equal to the number of irreducible characters of its Weyl group. The proof relies on the classification of ℓ -stubborn subgroups in compact Lie groups.