Modify android system libs but cannot get the log
<p>I modified the system lib(libnetutils) on android system but could not find a good way to test it.</p>

<p>I used this in my codes:</p>

<pre><code>#include &lt;android/log.h&gt; 
#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG, "tag", __VA_ARGS__)
LOGD("balabala");
</code></pre>

<p>I compiled the system lib to libnetutils.so file and replaced it on my test phone. The basic WiFi worked well, but I cound not see any logs in the logcat. Why?</p>
