Incorrect spec. Both search backends return :ok so that is what should be the spec.
lib/pleroma/search/database_search.ex:56:callback_type_mismatch
Type mismatch for @callback remove_from_index/1 in Pleroma.Search.SearchBackend behaviour.
Expected type:
{:error, _} | {:ok, _}
Actual type:
:ok
Lain Soykaf