diff --git a/chain/actors/actor_storagepower.go b/chain/actors/actor_storagepower.go
index c3ee5530c..53d021b11 100644
--- a/chain/actors/actor_storagepower.go
+++ b/chain/actors/actor_storagepower.go
@@ -747,10 +747,10 @@ func MinerSetRemove(ctx context.Context, vmctx types.VMContext, rcid cid.Cid, ma
 
 	mkey := string(maddr.Bytes())
 	switch nd.Delete(ctx, mkey) {
-	case hamt.ErrNotFound:
-		return cid.Undef, aerrors.New(1, "miner not found in set on delete")
 	default:
 		return cid.Undef, aerrors.HandleExternalError(err, "failed to delete miner from set")
+	case hamt.ErrNotFound:
+		return cid.Undef, aerrors.New(1, "miner not found in set on delete")
 	case nil:
 	}
 
diff --git a/chain/actors/actors.go b/chain/actors/actors.go
index 19de6a383..5208286a3 100644
--- a/chain/actors/actors.go
+++ b/chain/actors/actors.go
@@ -32,7 +32,7 @@ func mustIDAddress(i uint64) address.Address {
 }
 
 func init() {
-	pref := cid.NewPrefixV1(cid.Raw, mh.ID)
+	pref := cid.NewPrefixV1(cid.Raw, mh.IDENTITY)
 	mustSum := func(s string) cid.Cid {
 		c, err := pref.Sum([]byte(s))
 		if err != nil {
diff --git a/chain/blocksync/blocksync.go b/chain/blocksync/blocksync.go
index 873426d0b..a16bc78b0 100644
--- a/chain/blocksync/blocksync.go
+++ b/chain/blocksync/blocksync.go
@@ -108,7 +108,7 @@ func (bss *BlockSyncService) HandleStream(s inet.Stream) {
 }
 
 func (bss *BlockSyncService) processRequest(ctx context.Context, req *BlockSyncRequest) (*BlockSyncResponse, error) {
-	ctx, span := trace.StartSpan(ctx, "blocksync.ProcessRequest")
+	_, span := trace.StartSpan(ctx, "blocksync.ProcessRequest")
 	defer span.End()
 
 	opts := ParseBSOptions(req.Options)
diff --git a/chain/blocksync/blocksync_client.go b/chain/blocksync/blocksync_client.go
index 32c810511..127808092 100644
--- a/chain/blocksync/blocksync_client.go
+++ b/chain/blocksync/blocksync_client.go
@@ -12,9 +12,9 @@ import (
 	blocks "github.com/ipfs/go-block-format"
 	bserv "github.com/ipfs/go-blockservice"
 	"github.com/ipfs/go-cid"
+	host "github.com/libp2p/go-libp2p-core/host"
 	inet "github.com/libp2p/go-libp2p-core/network"
 	"github.com/libp2p/go-libp2p-core/peer"
-	host "github.com/libp2p/go-libp2p-host"
 	"go.opencensus.io/trace"
 	"golang.org/x/xerrors"
 
@@ -28,8 +28,7 @@ type BlockSync struct {
 	bserv bserv.BlockService
 	host  host.Host
 
-	syncPeersLk sync.Mutex
-	syncPeers   *bsPeerTracker
+	syncPeers *bsPeerTracker
 }
 
 func NewBlockSyncClient(bserv dtypes.ChainBlockService, h host.Host) *BlockSync {
diff --git a/chain/gen/gen.go b/chain/gen/gen.go
index 059db2be5..9c8bfadfb 100644
--- a/chain/gen/gen.go
+++ b/chain/gen/gen.go
@@ -15,7 +15,7 @@ import (
 	"github.com/ipfs/go-car"
 	offline "github.com/ipfs/go-ipfs-exchange-offline"
 	"github.com/ipfs/go-merkledag"
-	peer "github.com/libp2p/go-libp2p-peer"
+	peer "github.com/libp2p/go-libp2p-core/peer"
 	"go.opencensus.io/trace"
 	"golang.org/x/xerrors"
 
@@ -42,8 +42,6 @@ var log = logging.Logger("gen")
 const msgsPerBlock = 20
 
 type ChainGen struct {
-	accounts []address.Address
-
 	msgsPerBlock int
 
 	bs blockstore.Blockstore
diff --git a/chain/gen/utils.go b/chain/gen/utils.go
index dc4589585..34cdce95b 100644
--- a/chain/gen/utils.go
+++ b/chain/gen/utils.go
@@ -11,7 +11,7 @@ import (
 	hamt "github.com/ipfs/go-hamt-ipld"
 	blockstore "github.com/ipfs/go-ipfs-blockstore"
 	bstore "github.com/ipfs/go-ipfs-blockstore"
-	peer "github.com/libp2p/go-libp2p-peer"
+	peer "github.com/libp2p/go-libp2p-core/peer"
 	cbg "github.com/whyrusleeping/cbor-gen"
 	"golang.org/x/xerrors"
 
diff --git a/chain/messagepool/messagepool.go b/chain/messagepool/messagepool.go
index 369be86f6..1d0f3eb45 100644
--- a/chain/messagepool/messagepool.go
+++ b/chain/messagepool/messagepool.go
@@ -59,8 +59,7 @@ type MessagePool struct {
 
 	localAddrs map[address.Address]struct{}
 
-	pending      map[address.Address]*msgSet
-	pendingCount int
+	pending map[address.Address]*msgSet
 
 	curTsLk sync.Mutex // DO NOT LOCK INSIDE lk
 	curTs   *types.TipSet
@@ -79,9 +78,8 @@ type MessagePool struct {
 }
 
 type msgSet struct {
-	msgs       map[uint64]*types.SignedMessage
-	nextNonce  uint64
-	curBalance types.BigInt
+	msgs      map[uint64]*types.SignedMessage
+	nextNonce uint64
 }
 
 func newMsgSet() *msgSet {
@@ -572,9 +570,7 @@ func (mp *MessagePool) MessagesForBlocks(blks []*types.BlockHeader) ([]*types.Si
 		if err != nil {
 			return nil, xerrors.Errorf("failed to get messages for apply block %s(height %d) (msgroot = %s): %w", b.Cid(), b.Height, b.Messages, err)
 		}
-		for _, msg := range smsgs {
-			out = append(out, msg)
-		}
+		out = append(out, smsgs...)
 
 		for _, msg := range bmsgs {
 			smsg := mp.RecoverSig(msg)
diff --git a/chain/vm/vm.go b/chain/vm/vm.go
index 932488fd7..1eed0f895 100644
--- a/chain/vm/vm.go
+++ b/chain/vm/vm.go
@@ -521,7 +521,7 @@ func (vm *VM) ActorBalance(addr address.Address) (types.BigInt, aerrors.ActorErr
 }
 
 func (vm *VM) Flush(ctx context.Context) (cid.Cid, error) {
-	ctx, span := trace.StartSpan(ctx, "vm.Flush")
+	_, span := trace.StartSpan(ctx, "vm.Flush")
 	defer span.End()
 
 	from := vm.buf
diff --git a/cmd/lotus/main.go b/cmd/lotus/main.go
index e2f32c0a0..fb90b178a 100644
--- a/cmd/lotus/main.go
+++ b/cmd/lotus/main.go
@@ -72,5 +72,4 @@ func main() {
 		log.Warnf("%+v", err)
 		os.Exit(1)
 	}
-	return
 }
diff --git a/miner/miner.go b/miner/miner.go
index df2b3cdaa..307a495d2 100644
--- a/miner/miner.go
+++ b/miner/miner.go
@@ -191,7 +191,7 @@ eventLoop:
 				time.Sleep(time.Until(btime))
 			} else {
 				log.Warnw("mined block in the past", "block-time", btime,
-					"time", time.Now(), "duration", time.Now().Sub(btime))
+					"time", time.Now(), "duration", time.Since(btime))
 			}
 
 			mWon := make(map[address.Address]struct{})
diff --git a/node/repo/fsrepo.go b/node/repo/fsrepo.go
index b75138835..b41024e5d 100644
--- a/node/repo/fsrepo.go
+++ b/node/repo/fsrepo.go
@@ -29,7 +29,6 @@ const (
 	fsAPIToken  = "token"
 	fsConfig    = "config.toml"
 	fsDatastore = "datastore"
-	fsLibp2pKey = "libp2p.priv"
 	fsLock      = "repo.lock"
 	fsKeystore  = "keystore"
 )
diff --git a/peermgr/peermgr.go b/peermgr/peermgr.go
index 60714f219..624fcfcc5 100644
--- a/peermgr/peermgr.go
+++ b/peermgr/peermgr.go
@@ -27,7 +27,7 @@ type PeerMgr struct {
 
 	// peerLeads is a set of peers we hear about through the network
 	// and who may be good peers to connect to for expanding our peer set
-	peerLeads map[peer.ID]time.Time
+	//peerLeads map[peer.ID]time.Time // TODO: unused
 
 	peersLk sync.Mutex
 	peers   map[peer.ID]struct{}
diff --git a/retrieval/client.go b/retrieval/client.go
index 8936fbafb..405320a46 100644
--- a/retrieval/client.go
+++ b/retrieval/client.go
@@ -231,6 +231,9 @@ func (cst *clientStream) consumeBlockMessage(block Block, out io.Writer) (uint64
 	}
 
 	cid, err := prefix.Sum(block.Data)
+	if err != nil {
+		return 0, err
+	}
 
 	blk, err := blocks.NewBlockWithCid(block.Data, cid)
 	if err != nil {
diff --git a/storage/miner.go b/storage/miner.go
index dcb6b1155..7026ce1f8 100644
--- a/storage/miner.go
+++ b/storage/miner.go
@@ -3,7 +3,6 @@ package storage
 import (
 	"context"
 	"errors"
-	"sync"
 	"time"
 
 	"github.com/ipfs/go-cid"
@@ -36,10 +35,6 @@ type Miner struct {
 	maddr  address.Address
 	worker address.Address
 
-	// PoSt
-	postLk    sync.Mutex
-	schedPost uint64
-
 	// Sealing
 	sb      *sectorbuilder.SectorBuilder
 	sectors *statestore.StateStore