title: "Error: JAVA_HOME is not defined correctly." in building Jikes rvm
body: <p>When I built the Jikes RVM on Ubuntu, I got this error. Any idea?</p>
  
  <pre><code>bin/buildit localhost production
  ---&gt; Config: production
  /bin/bash --login -c  '/bin/bash --login -c  "   cd /home/jack/Programs/jikesrvm-3.1.2 &amp;&amp;  export JAVA_HOME=/opt/jdk1.6.0 &amp;&amp;   ant very-clean -Dhost.name=ia32-linux &amp;&amp;  ant check-components-properties -Dhost.name=ia32-linux -Dtarget.name=ia32-linux -Dcomponents.cache.dir=/home/jack/.buildit_components_cache  &amp;&amp;   ant -Dtarget.name=ia32-linux -Dconfig.name=production -Dhg.revision= -Dhost.name=ia32-linux -Dcomponents.cache.dir=/home/jack/.buildit_components_cache "' 
  Error: JAVA_HOME is not defined correctly.
    We cannot execute /opt/jdk1.6.0/bin/java
  Wed Jun 13 12:23:37 EDT 2012
  ===================== Summary =====================
  Local   : /home/jack/Programs/jikesrvm-3.1.2
  Build   : ubuntu:/home/jack/Programs/jikesrvm-3.1.2
  Target  : ubuntu:/home/jack/Programs/jikesrvm-3.1.2
  Start   : Wed Jun 13 12:23:37 EDT 2012
  Config  : production [FAILED Wed Jun 13 12:23:37 EDT 2012]
  ===================================================
  </code></pre>
  
  <p>OS:</p>
  
  <pre><code>Linux ubuntu 2.6.32-24-generic #39-Ubuntu SMP Wed Jul 28 06:07:29 UTC 2010 i686 GNU/Linux
  </code></pre>
  
  <p>Environmental Variables:
  PATH</p>
  
  <pre><code>/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/lib/jvm/java-6-sun-1.6.0.22/bin&lt;
  </code></pre>
  
  <p>JAVA_HOME</p>
  
  <pre><code>/usr/lib/jvm/java-6-sun-1.6.0.22
  </code></pre>
  
  <p>I checked the <code>java</code> in the <code>JAVA_HOME/bin</code> directory, it works.
  No matter how I change the environmental variables, the error kept complaining </p>
  
  <blockquote>
    <p>"We cannot execute /opt/jdk1.6.0/bin/java".</p>
  </blockquote>
  
  <p>It seems that I didn't modify the right "position".</p>