java.lang.AssertionError: only show error once expected [1] but found [0]

from JTR log:

#section:testng
----------messages:(3/139)----------
command: testng LogGeneratedClassesTest
reason: User specified action: run testng LogGeneratedClassesTest
elapsed time (seconds): 131.179
----------System.out:(52/3025)----------
[TestNG] Running:
  java/lang/invoke/lambda/LogGeneratedClassesTest.java

config LogGeneratedClassesTest.setup(): success
test LogGeneratedClassesTest.testDumpDirIsFile(): success
test LogGeneratedClassesTest.testDumpDirNotExist(): success
test LogGeneratedClassesTest.testDumpDirNotWritable(): failure
java.lang.AssertionError: only show error once expected [1] but found [0]
at org.testng.Assert.fail(Assert.java:94)
at org.testng.Assert.failNotEquals(Assert.java:494)
at org.testng.Assert.assertEquals(Assert.java:123)
at org.testng.Assert.assertEquals(Assert.java:265)
at LogGeneratedClassesTest.testDumpDirNotWritable(LogGeneratedClassesTest.java:186)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:484)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:84)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:714)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:901)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1231)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:127)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:111)
at org.testng.TestRunner.privateRun(TestRunner.java:767)
at org.testng.TestRunner.run(TestRunner.java:617)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:334)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:329)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:291)
at org.testng.SuiteRunner.run(SuiteRunner.java:240)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1224)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1149)
at org.testng.TestNG.run(TestNG.java:1057)
at com.sun.javatest.regtest.TestNGAction$TestNGRunner.main(TestNGAction.java:161)
at com.sun.javatest.regtest.TestNGAction$TestNGRunner.main(TestNGAction.java:145)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:484)
at com.sun.javatest.regtest.MainWrapper$MainThread.run(MainWrapper.java:94)
at java.lang.Thread.run(Thread.java:744)
test LogGeneratedClassesTest.testLogging(): success
test LogGeneratedClassesTest.testLoggingException(): success
test LogGeneratedClassesTest.testNotLogging(): success
config LogGeneratedClassesTest.cleanup(): success

===============================================
java/lang/invoke/lambda/LogGeneratedClassesTest.java
Total tests run: 6, Failures: 1, Skips: 0
===============================================