$ n zz_test.go
    1	package z
    2	
    3	func f() {
    4		_ = g[:]
    5	}
    6	
    7	var g [1]byte
    8	
    9	func f2() {
   10		for g := 0; g < 2; g++ {
   11			go func(g int) {
   12			}(g)
   13		}
   14	}
   15	
   16	var g interface{}
$ go test zz_test.go
# command-line-arguments
./zz_test.go:4:7: cannot slice g (type interface {})
./zz_test.go:16:5: g redeclared in this block
	previous declaration at ./zz_test.go:11:13
FAIL	command-line-arguments [build failed]
$