env = append(env, key+"="+val)
		}
	}

	return env, nil
}

var extraEnvKeys = []string{
	"SYSTEMROOT",         // must be preserved on Windows to find DLLs; golang.org/issue/25210
	"WINDIR",             // must be preserved on Windows to be able to run PowerShell command; golang.org/issue/30711
	"LD_LIBRARY_PATH",    // must be preserved on Unix systems to find shared libraries