From 2c401f90419535543e8f811c9ff4062959ff2e6c Mon Sep 17 00:00:00 2001
From: Aayush Rajasekaran <arajasek94@gmail.com>
Date: Fri, 12 Jun 2020 01:13:11 -0400
Subject: [PATCH 1/2] Improve UX of fetch-params

---
 .circleci/config.yml |  2 +-
 cli/params.go        | 18 ++++++++----------
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index ddcbd5481..fc9f495a8 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -45,7 +45,7 @@ commands:
             - 'v25-2k-lotus-params'
           paths:
             - /var/tmp/filecoin-proof-parameters/
-      - run:  ./lotus fetch-params --proving-params 2048
+      - run:  ./lotus fetch-params 2048
       - save_cache:
           name: Save parameters cache
           key: 'v25-2k-lotus-params'
diff --git a/cli/params.go b/cli/params.go
index 95596ff57..47e1e3988 100644
--- a/cli/params.go
+++ b/cli/params.go
@@ -10,18 +10,16 @@ import (
 )
 
 var fetchParamCmd = &cli.Command{
-	Name:  "fetch-params",
-	Usage: "Fetch proving parameters",
-	Flags: []cli.Flag{
-		&cli.StringFlag{
-			Name:  "proving-params",
-			Usage: "download params used creating proofs for given size, i.e. 32GiB",
-		},
-	},
+	Name:      "fetch-params",
+	Usage:     "Fetch proving parameters",
+	ArgsUsage: "[sectorSize]",
 	Action: func(cctx *cli.Context) error {
-		sectorSizeInt, err := units.RAMInBytes(cctx.String("proving-params"))
+		if !cctx.Args().Present() {
+			return xerrors.Errorf("must pass sector size to fetch params for (specify as \"32GiB\", for instance)")
+		}
+		sectorSizeInt, err := units.RAMInBytes(cctx.Args().First())
 		if err != nil {
-			return err
+			return xerrors.Errorf("error parsing sector size (specify as \"32GiB\", for instance): %w", err)
 		}
 		sectorSize := uint64(sectorSizeInt)
 

From 227819dc1e43fd9c64022fc3b79cb2ca907bc62c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Magiera?= <magik6k@gmail.com>
Date: Fri, 12 Jun 2020 10:03:31 +0200
Subject: [PATCH 2/2] docs: Update local-dev-net

---
 documentation/en/local-dev-net.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/documentation/en/local-dev-net.md b/documentation/en/local-dev-net.md
index 0b352fe8a..e11d9b358 100644
--- a/documentation/en/local-dev-net.md
+++ b/documentation/en/local-dev-net.md
@@ -8,7 +8,7 @@ make 2k
 
 Download the 2048 byte parameters:
 ```sh
-./lotus fetch-params --proving-params 2048
+./lotus fetch-params 2048
 ```
 
 Pre-seal some sectors: