linux/amd64, parent: 15991:4cdeb75811c7 tip

$ cat /tmp/test.go 
package main
import "net"
func main() {
    c, err := net.Dial("tmp", "")
    if err != nil {
        defer c.Close()
    }
}

$ go run /tmp/test.go
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x20 pc=0x41c8d3]

goroutine 1 [running]:
runtime.panic(0x4860b0, 0xc2000382c0)
    src/pkg/runtime/panic.c:246 +0xb1
runtime.panicstring(0x4f8c63)
    src/pkg/runtime/panic.c:479 +0xa3
runtime.sigpanic()
    src/pkg/runtime/thread_linux.c:214 +0x168
runtime.jmpdefer()
    src/pkg/runtime/asm_amd64.s:481 +0x13
main.main()
    /tmp/test.go:8 +0x7a
runtime.main()
    src/pkg/runtime/proc.c:279 +0xae
runtime.goexit()
    src/pkg/runtime/proc.c:316