unquote expect
txtar-c blah
! stderr .+
cmp stdout expect

-- blah/go.mod --
module example.com/blah

-- blah/main.go --
package main

import "fmt"

func main() {
  fmt.Println("Hello, world!")
}
-- blah/subdir/x --
x contents
-- expect --
>-- go.mod --
>module example.com/blah
>
>-- main.go --
>package main
>
>import "fmt"
>
>func main() {
>  fmt.Println("Hello, world!")
>}
>-- subdir/x --
>x contents