lesson, this is why you don't mock

app/jobs/scheduled/leader_promotions.rb

@@ -9,7 +9,7 @@ module Jobs
       User.real.where(trust_level: TrustLevel[3]).find_each do |u|
         # Don't demote too soon after being promoted
         next if UserHistory.for(u, :auto_trust_level_change)
-                           .where('created_at >= ?', SiteSetting.leader_promotion_min_duration.to_i.days.ago)
+                           .where('created_at >= ?', SiteSetting.tl3_promotion_min_duration.to_i.days.ago)
                            .where(previous_value: TrustLevel[2].to_s)
                            .where(new_value: TrustLevel[3].to_s)
                            .exists?

spec/jobs/leader_promotions_spec.rb

@@ -28,7 +28,7 @@ describe Jobs::LeaderPromotions do
     end
 
     before do
-      SiteSetting.stubs(:leader_promotion_min_duration).returns(3)
+      SiteSetting.tl3_promotion_min_duration = 3
     end
 
     it "demotes if was promoted more than X days ago" do