diff --git a/cmd/coordinator/coordinator.go b/cmd/coordinator/coordinator.go
index ee13e13f83..d3b3b3d823 100644
--- a/cmd/coordinator/coordinator.go
+++ b/cmd/coordinator/coordinator.go
@@ -1383,6 +1383,14 @@ func (ts *trySet) notifyStarting() {
 	}
 	msg := name + " beginning. Status page: https://farmer.golang.org/try?commit=" + ts.Commit[:8]
 
+	// If any of the requested SlowBot builders
+	// have a known issue, give users a warning.
+	for _, b := range ts.slowBots {
+		if b.KnownIssue != 0 {
+			msg += fmt.Sprintf("\nNote that builder %s has a known issue golang.org/issue/%d.", b.Name, b.KnownIssue)
+		}
+	}
+
 	gerritClient := pool.NewGCEConfiguration().GerritClient()
 	ctx := context.Background()
 	if ci, err := gerritClient.GetChangeDetail(ctx, ts.ChangeTriple()); err == nil {
diff --git a/dashboard/builders.go b/dashboard/builders.go
index ed8a895a95..ceb63b5287 100644
--- a/dashboard/builders.go
+++ b/dashboard/builders.go
@@ -1760,7 +1760,8 @@ func init() {
 			GOARM:              "7",
 			AlwaysCrossCompile: false,
 		},
-		tryBot:            nil, // Issue 22748, Issue 22749
+		tryBot:            nil, // Issues #22748, #22749, #35628, #40872.
+		KnownIssue:        35628,
 		FlakyNet:          true,
 		numTestHelpers:    2,
 		numTryTestHelpers: 7,