cardano-node/src/Cardano/Node/Protocol/Cardano.hs:(216,14)-(218,79): Suggestion: Replace case with maybe
Found:
  case npcTestBabbageHardForkAtEpoch of
    Nothing -> Consensus.CardanoTriggerHardForkAtDefaultVersion
    Just epochNo -> Consensus.CardanoTriggerHardForkAtEpoch epochNo
Perhaps:
  maybe
    Consensus.CardanoTriggerHardForkAtDefaultVersion
    Consensus.CardanoTriggerHardForkAtEpoch
    npcTestBabbageHardForkAtEpoch

cardano-node/src/Cardano/Node/Protocol/Cardano.hs:(220,14)-(222,79): Suggestion: Replace case with maybe
Found:
  case npcTestConwayHardForkAtEpoch of
    Nothing -> Consensus.CardanoTriggerHardForkAtDefaultVersion
    Just epochNo -> Consensus.CardanoTriggerHardForkAtEpoch epochNo
Perhaps:
  maybe
    Consensus.CardanoTriggerHardForkAtDefaultVersion
    Consensus.CardanoTriggerHardForkAtEpoch
    npcTestConwayHardForkAtEpoch

cardano-node/src/Cardano/Node/Tracing/Tracers/ChainDB.hs:1580:39-72: Warning: Redundant bracket
Found:
  (LedgerDB.TraceForkerEventWithKey)
Perhaps:
  LedgerDB.TraceForkerEventWithKey

cardano-node/src/Cardano/Node/Tracing/Tracers/ChainDB.hs:1582:39-72: Warning: Redundant bracket
Found:
  (LedgerDB.FlavorImplSpecificTrace)
Perhaps:
  LedgerDB.FlavorImplSpecificTrace

cardano-node/src/Cardano/Tracing/OrphanInstances/Consensus.hs:24:1-46: Warning: Use fewer imports
Found:
  import Ouroboros.Network.Block ( MaxSlotNo(..) )
  import Ouroboros.Network.Block
      ( BlockNo(..),
        ChainUpdate(..),
        SlotNo(..),
        StandardHash,
        Tip(..),
        blockHash,
        pointSlot,
        tipFromHeader )
  
Perhaps:
  import Ouroboros.Network.Block
      ( MaxSlotNo(..),
        BlockNo(..),
        ChainUpdate(..),
        SlotNo(..),
        StandardHash,
        Tip(..),
        blockHash,
        pointSlot,
        tipFromHeader )
  

cardano-node/src/Cardano/Tracing/OrphanInstances/Network.hs:(87,1)-(88,52): Warning: Use fewer imports
Found:
  import Ouroboros.Network.PeerSelection.State.LocalRootPeers
      ( HotValency(..), LocalRootPeers, WarmValency(..) )
  import Ouroboros.Network.PeerSelection.State.LocalRootPeers
      ( LocalRootConfig(..) )
  import qualified Ouroboros.Network.PeerSelection.State.LocalRootPeers as LocalRootPeers
  
Perhaps:
  import Ouroboros.Network.PeerSelection.State.LocalRootPeers
      ( HotValency(..),
        LocalRootPeers,
        WarmValency(..),
        LocalRootConfig(..) )
  import qualified Ouroboros.Network.PeerSelection.State.LocalRootPeers as LocalRootPeers
  

trace-forward/src/Trace/Forward/Protocol/DataPoint/Type.hs:2:1-26: Warning: Unused LANGUAGE pragma
Found:
  {-# LANGUAGE EmptyCase #-}
Perhaps you should remove it.

trace-forward/src/Trace/Forward/Protocol/TraceObject/Forwarder.hs:8:1-33: Warning: Unused LANGUAGE pragma
Found:
  {-# LANGUAGE TypeApplications #-}
Perhaps you should remove it.

trace-forward/src/Trace/Forward/Protocol/TraceObject/Type.hs:5:1-26: Warning: Unused LANGUAGE pragma
Found:
  {-# LANGUAGE EmptyCase #-}
Perhaps you should remove it.

16 hints
=====================================================================
Note: to ignore a particular hint (e.g. "Reduce duplication"), write
this in the source file:
{-# ANN module ("HLint: ignore Reduce duplication" :: Text) #-}
You can also apply it just to a particular function, which is better:
{-# ANN funcName ("HLint: ignore Reduce duplication" :: Text) #-}