Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

1.8.3

What operating system and processor architecture are you using (go env)?

Linux on x86-64

Code sample

package main

import (
	"testing"
	"flag"
)

func main() {
	println("hi")
	flag.Parse()
}

func a(t *testing.T) {
}

Observe that, once compiled, test flags are added into the executable:

> go build -o main
> ./main -help   
hi                        
Usage of ./main:     
  -test.bench regexp      
        run only benchmarks matching regexp
  -test.benchmem
        print memory allocations for benchmarks
......
......

What did you expect to see?

The function a uses testing package, however, since the function is dead code to the entire program, the testing package features are never utilised and test flags should never have been compiled into the executable.