beam_PostCommit_PortableJar_Flink and beam_PostCommit_PortableJar_Spark failing

Task :runners:flink:1.10:job-server:testJavaJarCreatorPy37 is failing:

11:23:49 Traceback (most recent call last):
11:23:49 File "<string>", line 24, in <module>
11:23:49 File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_PortableJar_Flink/src/sdks/python/apache_beam/runners/portability/portable_runner.py", line 545, in wait_until_finish
11:23:49 (self._job_id, self._state, self._last_error_message()))
11:23:49 RuntimeError: Pipeline BeamApp-jenkins-0323182347-56de7e22_388a77e1-7cd2-40cd-a0b8-5ea029aba475 failed in state FAILED: java.lang.IllegalArgumentException: Expected exactly one jar on sun.misc.Launcher$AppClassLoader@1b6d3586

Same error for :runners:spark:job-server:testJavaJarCreatorPy37.