Merge pull request #2931 from cfromknecht/channel-backup-flake

lnd_test: use WaitNoError when testing num singles in...

lnd_test.go

@@ -13378,21 +13378,32 @@ func testExportChannelBackup(net *lntest.NetworkHarness, t *harnessTest) {
 	// Before we proceed, we'll make two utility methods we'll use below
 	// for our primary assertions.
 	assertNumSingleBackups := func(numSingles int) {
+		err := lntest.WaitNoError(func() error {
 			ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
 			req := &lnrpc.ChanBackupExportRequest{}
-		chanSnapshot, err := carol.ExportAllChannelBackups(ctxt, req)
+			chanSnapshot, err := carol.ExportAllChannelBackups(
+				ctxt, req,
+			)
 			if err != nil {
-			t.Fatalf("unable to export channel backup: %v", err)
+				return fmt.Errorf("unable to export channel "+
+					"backup: %v", err)
 			}
 
 			if chanSnapshot.SingleChanBackups == nil {
-			t.Fatalf("single chan backups not populated")
+				return fmt.Errorf("single chan backups not " +
+					"populated")
 			}
 
 			backups := chanSnapshot.SingleChanBackups.ChanBackups
 			if len(backups) != numSingles {
-			t.Fatalf("expected %v singles, got %v", len(backups),
+				return fmt.Errorf("expected %v singles, "+
-				numSingles)
+					"got %v", len(backups), numSingles)
+			}
+
+			return nil
+		}, defaultTimeout)
+		if err != nil {
+			t.Fatalf(err.Error())
 		}
 	}
 	assertMultiBackupFound := func() func(bool, map[wire.OutPoint]struct{}) {