Liferay 6.2: SassToCssBuilder has got NullPointerException, - liferay

Question

Now, I have problem when I build portlet to war file in eclipse.
Env:
- liferay-plugins-sdk-6.2.0
- liferay-portal-6.2-ce-ga2
Issue: use eclipse to build the portlet to war file successfully, but I have the error:
build-css:
[java] Loading jar:file:/home/tomcat-7.0.53/webapps/ROOT/WEB-INF/lib/portal-impl.jar!/system.properties
[java] Loading jar:file:/home/tomcat-7.0.53/webapps/ROOT/WEB-INF/lib/portal-impl.jar!/portal.properties
[java] java.lang.NullPointerException
[java] at com.liferay.portal.tools.SassToCssBuilder._parseSassDirectory(SassToCssBuilder.java:222)
[java] at com.liferay.portal.tools.SassToCssBuilder.(SassToCssBuilder.java:144)
[java] at com.liferay.portal.tools.SassToCssBuilder.main(SassToCssBuilder.java:94)
Please, give me any suggestion to fix this problem!
I am waiting for all you help!
Thanks and Kind Regards,

Answer 1

I have found the root cause is the Tomcat-server that I changed. So, I have to use the tomcat-server of Liferay to build the portlet to pass that error.
Regards,

Answer 2

Try to comment out the goal build-css as mentioned here enter link description here
we want to just forward that request to the CSSBuilderMojo and not require the invoking from jars in portal directory
<plugin>
<groupId>com.liferay.maven.plugins</groupId>
<artifactId>liferay-maven-plugin</artifactId>
<version>${liferay.maven.plugin.version}</version>
<executions>
<!--<execution>-->
<!--<phase>generate-sources</phase>-->
<!--<goals>-->
<!--<goal>build-css</goal>-->
<!--</goals>-->
<!--</execution>-->
</executions>
</plugin>