diff --git a/cmd/lotus-bench/main.go b/cmd/lotus-bench/main.go
index 3b5927c88..1180a5723 100644
--- a/cmd/lotus-bench/main.go
+++ b/cmd/lotus-bench/main.go
@@ -360,7 +360,7 @@ func main() {
 			}
 
 			log.Info("generating election post candidates")
-			fcandidates, err := sb.GenerateEPostCandidates(sealedSectors, abi.PoStRandomness(challenge[:]), []abi.SectorNumber{})
+			fcandidates, err := sb.GenerateEPostCandidates(sealedSectors, challenge[:], []abi.SectorNumber{})
 			if err != nil {
 				return err
 			}
@@ -469,7 +469,7 @@ func main() {
 	}
 
 	if err := app.Run(os.Args); err != nil {
-		log.Warn(err)
+		log.Warnf("%+v", err)
 		return
 	}
 }
diff --git a/go.mod b/go.mod
index 7acee6f9c..f9c3738d8 100644
--- a/go.mod
+++ b/go.mod
@@ -21,7 +21,7 @@ require (
 	github.com/filecoin-project/go-fil-markets v0.0.0-20200304003055-d449a980d4bd
 	github.com/filecoin-project/go-padreader v0.0.0-20200210211231-548257017ca6
 	github.com/filecoin-project/go-paramfetch v0.0.2-0.20200218225740-47c639bab663
-	github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200306043753-5cdbe369b47d
+	github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200306215829-15085af52c2b
 	github.com/filecoin-project/go-statemachine v0.0.0-20200226041606-2074af6d51d9
 	github.com/filecoin-project/go-statestore v0.1.0
 	github.com/filecoin-project/specs-actors v0.0.0-20200306043603-709a3ce21094
diff --git a/go.sum b/go.sum
index 45317d78d..4cb5a6d96 100644
--- a/go.sum
+++ b/go.sum
@@ -122,6 +122,8 @@ github.com/filecoin-project/go-paramfetch v0.0.2-0.20200218225740-47c639bab663/g
 github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200226210935-4739f8749f56/go.mod h1:tzTc9BxxSbjlIzhFwm5h9oBkXKkRuLxeiWspntwnKyw=
 github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200306043753-5cdbe369b47d h1:tRS0QB50rhUaetohnt3GwKNGk28WOhkdniHvP461HXc=
 github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200306043753-5cdbe369b47d/go.mod h1:NcE+iL0bbYnamGmYQgCPVGbSaf8VF2/CLra/61B3I3I=
+github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200306215829-15085af52c2b h1:/08Z7ZXHt1qRGz1Ipd0suMgJOmuind8MDwG9va+OPz0=
+github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200306215829-15085af52c2b/go.mod h1:NcE+iL0bbYnamGmYQgCPVGbSaf8VF2/CLra/61B3I3I=
 github.com/filecoin-project/go-statemachine v0.0.0-20200226041606-2074af6d51d9 h1:k9qVR9ItcziSB2rxtlkN/MDWNlbsI6yzec+zjUatLW0=
 github.com/filecoin-project/go-statemachine v0.0.0-20200226041606-2074af6d51d9/go.mod h1:FGwQgZAt2Gh5mjlwJUlVB62JeYdo+if0xWxSEfBD9ig=
 github.com/filecoin-project/go-statestore v0.1.0 h1:t56reH59843TwXHkMcwyuayStBIiWBRilQjQ+5IiwdQ=