build failed,java returned 95

Question

run-signature-test:
     [echo] Referenced_JSR289API_JAR=./build/standard/bin/servlet-api.jar
   [delete] Deleting directory dev\build\sipservlet-tck\tck\report\sig_report
    [mkdir] Created dir:dev\build\sipservlet-tck\tck\report\sig_report
     [java] STATUS:Passed.BUILD FAILED
report.xml:342: The following error occurred while executing this line:
dev\report.xml:334: The following error occurred while executing this line:
dev\build\sipservlet-tck\tck\build.xml:1912: The following error occurred while executing this line:
dev\build\sipservlet-tck\tck\build.xml:339: The following error occurred while executing this line:
dev\build\sipservlet-tck\tck\build.xml:1805: Java returned: 95 在什么情况下会发生java returned:95 这样的错误呢?这是tck的builed过程,这个测试已经通过了.
1805行: <java fork="yes" failonerror="yes" classname="com.sun.tdk.signaturetest.SignatureTest">