fix the --no-pivot flag being ignored by ctr tasks start

Signed-off-by: Iceber Gu <wei.cai-nat@daocloud.io>

cmd/ctr/commands/tasks/start.go

@@ -31,7 +31,7 @@ var startCommand = cli.Command{
 	Name:      "start",
 	Usage:     "start a container that has been created",
 	ArgsUsage: "CONTAINER",
-	Flags: []cli.Flag{
+	Flags: append(platformStartFlags, []cli.Flag{
 		cli.BoolFlag{
 			Name:  "null-io",
 			Usage: "send all IO to /dev/null",
@@ -52,7 +52,7 @@ var startCommand = cli.Command{
 			Name:  "detach,d",
 			Usage: "detach from the task after it has started execution",
 		},
-	},
+	}...),
 	Action: func(context *cli.Context) error {
 		var (
 			err    error

cmd/ctr/commands/tasks/tasks_unix.go

@@ -34,11 +34,11 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-func init() {
-	startCommand.Flags = append(startCommand.Flags, cli.BoolFlag{
+var platformStartFlags = []cli.Flag{
+	cli.BoolFlag{
 		Name:  "no-pivot",
 		Usage: "disable use of pivot-root (linux only)",
-	})
+	},
 }
 
 // HandleConsoleResize resizes the console

cmd/ctr/commands/tasks/tasks_windows.go

@@ -29,6 +29,8 @@ import (
 	"github.com/urfave/cli"
 )
 
+var platformStartFlags = []cli.Flag{}
+
 // HandleConsoleResize resizes the console
 func HandleConsoleResize(ctx gocontext.Context, task resizer, con console.Console) error {
 	// do an initial resize of the console