Write an ImpTest to reproduce #5170

eras/conway/impl/testlib/Test/Cardano/Ledger/Conway/Imp/RatifySpec.hs

@@ -198,6 +198,46 @@ spoAndCCVotingSpec = do
         else do
           getLastEnactedParameterChange `shouldReturn` SNothing
           newRefScriptBaseFee `shouldBe` initialRefScriptBaseFee
+    -- https://github.com/IntersectMBO/cardano-ledger/issues/5170
+    -- TODO: Re-enable after issue is resolved, by removing this override
+    disableInConformanceIt "Constitution cannot be changed if active committee size is below min size"
+      . whenPostBootstrap
+      $ do
+        modifyPParams $ \pp ->
+          pp
+            & ppDRepVotingThresholdsL . dvtUpdateToConstitutionL .~ (0 %! 1)
+            & ppCommitteeMinSizeL .~ 2
+            & ppCommitteeMaxTermLengthL .~ EpochInterval 50
+        coldCommitteeActive <- KeyHashObj <$> freshKeyHash
+        coldCommitteeInactive <- KeyHashObj <$> freshKeyHash
+        startingEpoch <- getsNES nesELL
+        maxTermLength <- getsPParams ppCommitteeMaxTermLengthL
+        (dRep, _, _) <- setupSingleDRep 1_000_000_000
+        (spo, _, _) <- setupPoolWithStake $ Coin 1_000_000_000
+        let
+          committeeMap =
+            [ (coldCommitteeActive, addEpochInterval startingEpoch maxTermLength)
+            , (coldCommitteeInactive, addEpochInterval startingEpoch $ EpochInterval 5)
+            ]
+        initialCommittee <- getCommitteeMembers
+        committeeActionId <-
+          impAnn "Submit committee update"
+            . submitGovAction
+            $ UpdateCommittee
+              SNothing
+              initialCommittee
+              committeeMap
+              (0 %! 1)
+        submitYesVote_ (DRepVoter dRep) committeeActionId
+        submitYesVote_ (StakePoolVoter spo) committeeActionId
+        passNEpochs 2
+        getCommitteeMembers `shouldReturn` Map.keysSet committeeMap
+        passNEpochs 3
+        newConstitution <- arbitrary
+        constitutionActionId <- submitGovAction $ NewConstitution SNothing newConstitution
+        logRatificationChecks constitutionActionId
+        passNEpochs 2
+        getConstitution `shouldNotReturn` newConstitution
 
 committeeExpiryResignationDiscountSpec ::
   forall era.