weird Finset CI error

Stream: mathlib4

[Johan Commelin]

Does someone understand this error https://github.com/leanprover-community/mathlib4/pull/9379/files#diff-03fbfec778354ed3b5d86d12c3f7e7eef75d21dc272cbca0b9897f6a1815a486

ambiguous namespace 'Finset', possible interpretations: '[Finset, Finset.Finset]'

All that #9379 is doing, is renaming Finset.card_doubleton to Finset.card_pair.

[Yaël Dillies]

@[deprecated] alias Finset.card_doubleton := Finset.card_pair creates a lemma in namespace Finset.Finset

[Ruben Van de Velde]

Shouldn't the linter catch that? Or is that too late?