How to get full stack traces logged when a JUnit test running in ant fails?

Question

When a JUnit test throws a runtime exception while running in Eclipse, you can see the entire stack trace.

Our build server uses ant and runs JUnit, but the printout

Answer 1

There is a setting in JUnit BaseTestRunner limiting this value:

/**
  * Truncates a String to the maximum length.
  */
public static String truncate(String s) {
    if (fgMaxMessageLength != -1 && s.length() > fgMaxMessageLength)
        s= s.substring(0, fgMaxMessageLength)+"...";
    return s;
}

You can change this value by setting:

BaseTestRunner.setPreference("maxmessage", "-1");

Answer 2

I've posted this answer to this question before realizing that it was a duplicate of yours.

Here is my junit tag that does produce the exception trace.

<junit
  showoutput="yes"
  errorProperty="test.failed"
  failureProperty="test.failed"
  haltOnFailure="${test.halt-on-failure}"
  fork="yes"
  forkmode="${junit.forkmode}"
>
  <classpath>
    <pathelement location="${classes.dir}"/>
    <pathelement location="${classes-under-test.classes.dir}" />
  </classpath>

  <!-- #Formatters for capture and display -->
  <formatter
    type="brief"
    usefile="false"
  />
  <formatter type="brief" />
  <formatter
    type="xml"
    if="test.generate.xml.output"
  />

  <!-- #Test case isolation technique -->
  <test
    name="${testcase}"
    if="testcase"
  />

  <batchtest
    todir="${test.data.dir}"
    unless="testcase"
  >
    <fileset dir="${classes.dir}">
      <include name="**/Test*.class" />
      <exclude name="**/Test*$*.class" />
    </fileset>
  </batchtest>

</junit>

I think the one nested element that will do it for you is

  <formatter
    type="brief"
    usefile="false"
  />