I have a simple project that I am trying to build using Ant. My project contains testng, but I get an error message when I try to run the build. Could you please help me? I have spent a lot of time trying to see what's the problem but without any results so far.

Here is the project:

```
package selenium;

import org.testng.annotations.Test;

public class HomePage {

    @Test
    public void test(){

        System.out.println("this is test");
    }
}

```

Now I have a lib file that contains the testng.jar, and I have a test.xml suite that runs the class, and here is my build file:

```html
    <?xml version="1.0" encoding="UTF-8"?>

<project name="Concep.TestAutomation" basedir="." default="all">

 <property name="src.dir" value="${basedir}/src" />
 <property name="build.dir" value="target" />
 <property name="classes.dir" value="${build.dir}/classes" /> 
 <property name="suites.dir" value="suites" />
 <property name="testng.path" value="lib/testng.jar" />

 <property name="testreport.dir" value="${build.dir}/test-output" />

 <target name="clean" description="Delete the build directory.">
  <delete dir="${build.dir}" />
 </target>

 <target name="init" depends="clean" description="Create build directories.">
  <!--Create the build directory structure used by compile -->
  <mkdir dir="${build.dir}" />
  <mkdir dir="${classes.dir}" />
  <mkdir dir="${testreport.dir}" />
 </target>

 <target name="compile" depends="init" description="Compile tests.">
  <!-- Compile the java code from ${src} into ${classes.dir} -->
  <javac srcdir="${src.dir}" destdir="${classes.dir}" debug="true" />
 </target>

 <target name="run-test" depends="compile" description="Run test suite.">
  <!-- Run a testng suite-->
  <taskdef resource="testngtasks" classpath="${testng.path}" />

  <testng classpathref="${testng.path}" outputDir="${testreport.dir}" haltonfailure="true" verbose="5">
   <xmlfileset dir="${suites.dir}" includes="IA-smoke-test.xml" />
   </testng>
 </target>

 <target name="all" depends="run-test" description="Executes all targets." />

  <target name="all-debug" description="outputs all vars in use.">
  <!-- useful to diagnose runtime problems --> 
       <echo message="'work.dir' = '${basedir}/..'"/>
       <echo message="'lib.dir' = '${basedir}/lib'"/>
       <echo message="'src.dir' = '${basedir}/src'"/>
       <echo message="'config.dir' = '${basedir}/config'"/>
       <echo message="'build.dir' = 'target'"/>
       <echo message="'classes.dir' = '${build.dir}/classes'"/>
       <echo message="'suites.dir' = '${basedir}/suites'"/>
       <echo message="'testng.path' = '${basedir}/lib/testng.jar'"/>
     </target>

</project>
```