Here's the exception stacktrace for reference:

           Caused by: org.jboss.shrinkwrap.api.exporter.ArchiveExportException: File could not be created: \tmp\wsba-coordinatorcompletition-test.war
    at org.jboss.shrinkwrap.impl.base.exporter.AbstractStreamExporterImpl.getOutputStreamToFile(AbstractStreamExporterImpl.java:95)
    at org.jboss.shrinkwrap.impl.base.exporter.AbstractStreamExporterImpl.exportTo(AbstractStreamExporterImpl.java:144)
    at org.jboss.as.test.xts.wsba.coordinatorcompletion.client.BACoordinatorCompletionTestCase.createTestArchive(BACoordinatorCompletionTestCase.java:84)
    ... 59 more