From 95cf57744726b860533481cc2362a47a4bfbf462 Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Sat, 12 Jun 2021 12:02:36 -0700
Subject: [PATCH] fix(lotus-sim): really cancel walk immediately

---
 cmd/lotus-sim/simulation/simulation.go | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/cmd/lotus-sim/simulation/simulation.go b/cmd/lotus-sim/simulation/simulation.go
index ef4278178..0b8ab1e56 100644
--- a/cmd/lotus-sim/simulation/simulation.go
+++ b/cmd/lotus-sim/simulation/simulation.go
@@ -401,12 +401,11 @@ func (sim *Simulation) Walk(
 	grp.Go(func() error {
 		qs := resultQs
 		for len(qs) > 0 {
-			if err := ctx.Err(); err != nil {
-				return ctx.Err()
-			}
-
 			newQs := qs[:0]
 			for _, q := range qs {
+				if err := ctx.Err(); err != nil {
+					return ctx.Err()
+				}
 				select {
 				case r, ok := <-q:
 					if !ok {