title: set environment variable `ANDROID_NDK_HOME`
body: <p>I am using macbook. I have downloaded <a href="http://developer.android.com/ndk/downloads/index.html" rel="nofollow">Android NDK</a> &amp; extracted it to </p>
  
  <pre><code>~/mytool/android-ndk-r10e
  </code></pre>
  
  <p>In <strong>.bash_profile</strong> I have set :</p>
  
  <pre><code>export ANDROID_HOME=~/Library/Android/sdk
  export ANDROID_NDK_HOME = ~/mytool/android-ndk-r10e
  </code></pre>
  
  <p>My project pom.xml contains the following plugin:</p>
  
  <pre><code>&lt;plugin&gt;
     &lt;groupId&gt;com.simpligility.maven.plugins&lt;/groupId&gt;
     &lt;artifactId&gt;android-maven-plugin&lt;/artifactId&gt;
     &lt;version&gt;4.3.0&lt;/version&gt;
     &lt;extensions&gt;true&lt;/extensions&gt;
  &lt;/plugin&gt;
  </code></pre>
  
  <p>When I run <code>mvn clean install</code>, I got the following error:</p>
  
  <pre><code>[ERROR] Failed to execute goal com.simpligility.maven.plugins:android-maven-plugin:4.3.0:ndk-build (default-ndk-build) on project MyTrackor: No Android NDK path could be found. 
  
  You may configure it in the pom using &lt;ndk&gt;&lt;path&gt;...&lt;/path&gt;&lt;/ndk&gt; or &lt;properties&gt;&lt;ndk.path&gt;...&lt;/ndk.path&gt;&lt;/properties&gt; or on command-line using -Dandroid.ndk.path=... or by setting environment variable ANDROID_NDK_HOME -&gt; [Help 1]
  </code></pre>
  
  <p>The above error complains that no Android NDK path could be found, and it suggests me to set environment variable <code>ANDROID_NDK_HOME</code> to resolve the problem. </p>
  
  <p>But as you see in my <strong>.bash_profile</strong>, I have already set the envrionment variable <code>ANDROID_NDK_HOME</code>. Why I still get this error ?</p>