! cue cmd errcode
! stdout .
stderr '^task failed: command "ls --badflags" failed: exit status [12]$'

-- task.cue --
package home
message: "Hello world!"

-- task_tool.cue --
package home

import "tool/exec"

command: errcode: {
	task: bad: exec.Run & {
		kind:   "exec"
		cmd:    "ls --badflags"
		stderr: string // suppress error message
	}}