test_set_requirements_with_cached_directory failed on travis

E                   Caused by: org.apache.beam.vendor.guava.v26_0_jre.com.google.common.util.concurrent.UncheckedExecutionException: java.lang.IllegalStateException: Process died with exit code 0
E                   	at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2050)
E                   	at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache.get(LocalCache.java:3952)
E                   	at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache.getOrLoad(LocalCache.java:3974)
E                   	at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4958)
E                   	at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4964)
E                   	at org.apache.beam.runners.fnexecution.control.DefaultJobBundleFactory$SimpleStageBundleFactory.<init>(DefaultJobBundleFactory.java:211)
E                   	at org.apache.beam.runners.fnexecution.control.DefaultJobBundleFactory$SimpleStageBundleFactory.<init>(DefaultJobBundleFactory.java:202)
E                   	at org.apache.beam.runners.fnexecution.control.DefaultJobBundleFactory.forStage(DefaultJobBundleFactory.java:185)
E                   	at org.apache.flink.python.AbstractPythonFunctionRunner.open(AbstractPythonFunctionRunner.java:179)
E                   	at org.apache.flink.table.runtime.operators.python.AbstractPythonScalarFunctionOperator$ProjectUdfInputPythonScalarFunctionRunner.open(AbstractPythonScalarFunctionOperator.java:193)
E                   	at org.apache.flink.streaming.api.operators.python.AbstractPythonFunctionOperator.open(AbstractPythonFunctionOperator.java:139)
E                   	at org.apache.flink.table.runtime.operators.python.AbstractPythonScalarFunctionOperator.open(AbstractPythonScalarFunctionOperator.java:143)
E                   	at org.apache.flink.table.runtime.operators.python.BaseRowPythonScalarFunctionOperator.open(BaseRowPythonScalarFunctionOperator.java:86)
E                   	at org.apache.flink.streaming.runtime.tasks.StreamTask.initializeStateAndOpen(StreamTask.java:1007)
E                   	at org.apache.flink.streaming.runtime.tasks.StreamTask.lambda$beforeInvoke$0(StreamTask.java:454)
E                   	at org.apache.flink.streaming.runtime.tasks.StreamTaskActionExecutor$SynchronizedStreamTaskActionExecutor.runThrowing(StreamTaskActionExecutor.java:94)
E                   	at org.apache.flink.streaming.runtime.tasks.StreamTask.beforeInvoke(StreamTask.java:449)
E                   	at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:461)
E                   	at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:707)
E                   	at org.apache.flink.runtime.taskmanager.Task.run(Task.java:532)
E                   	at java.lang.Thread.run(Thread.java:748)
E                   Caused by: java.lang.IllegalStateException: Process died with exit code 0
E                   	at org.apache.beam.runners.fnexecution.environment.ProcessManager$RunningProcess.isAliveOrThrow(ProcessManager.java:74)
E                   	at org.apache.beam.runners.fnexecution.environment.ProcessEnvironmentFactory.createEnvironment(ProcessEnvironmentFactory.java:125)
E                   	at org.apache.beam.runners.fnexecution.control.DefaultJobBundleFactory$1.load(DefaultJobBundleFactory.java:178)
E                   	at org.apache.beam.runners.fnexecution.control.DefaultJobBundleFactory$1.load(DefaultJobBundleFactory.java:162)
E                   	at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3528)
E                   	at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2277)
E                   	at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2154)
E                   	at org.apache.beam.vendor.guava.v26_0_jre.com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2044)
E                   	... 20 more