Jenkins JUnit returns null - junit

Question

In my scripted pipeline, I'm calling junit as follows
junit "${log_dir}/${os_version}/*.xml"
However, it's giving result as follows
Recording test results
null
Then a bunch of null exceptions.
at hudson.remoting.Channel.attachCallSiteStackTrace(Channel.java:1788)
at hudson.remoting.UserRequest$ExceptionResponse.retrieve(UserRequest.java:356)
at hudson.remoting.Channel.call(Channel.java:998)
at hudson.FilePath.act(FilePath.java:1069)
at hudson.FilePath.act(FilePath.java:1058)
at hudson.tasks.junit.JUnitParser.parseResult(JUnitParser.java:107)
at hudson.tasks.junit.JUnitResultArchiver.parse(JUnitResultArchiver.java:149)
at hudson.tasks.junit.JUnitResultArchiver.parseAndSummarize(JUnitResultArchiver.java:243)
at hudson.tasks.junit.pipeline.JUnitResultsStepExecution.run(JUnitResultsStepExecution.java:63)
at hudson.tasks.junit.pipeline.JUnitResultsStepExecution.run(JUnitResultsStepExecution.java:29)
at org.jenkinsci.plugins.workflow.steps.SynchronousNonBlockingStepExecution.lambda$start$0(SynchronousNonBlockingStepExecution.java:47)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
java.lang.NullPointerException
at hudson.tasks.junit.CaseResult.getPackageName(CaseResult.java:399)
at hudson.tasks.junit.TestResult.tally(TestResult.java:795)
at hudson.tasks.junit.JUnitParser$ParseResultCallable.invoke(JUnitParser.java:145)
at hudson.FilePath$FileCallableWrapper.call(FilePath.java:3073)
at hudson.remoting.UserRequest.perform(UserRequest.java:211)
at hudson.remoting.UserRequest.perform(UserRequest.java:54)
at hudson.remoting.Request$2.run(Request.java:369)
at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:72)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
My xml file looks as follows
<testsuites>
<testsuite errors="1" failures="0" tests="1" time="0">
<testcase name="workspace/inventory/group1">
<failure file="workspace/inventory/group1" line="94" message="[E201] Trailing whitespace" type="Ansible Lint">[E201] Trailing whitespace</failure>
</testcase>
</testsuite>
</testsuites>`

Answer 1

Fixed by adding .yml extension to filename which is being linted. So now the <failure> and <testcase> tag lines looks as follows
<testcase name="workspace/inventory/group1.yml">
<failure file="workspace/inventory/group1.yml" line="94" message="[E201] Trailing whitespace" type="Ansible Lint">[E201] Trailing whitespace</failure>
Now junit is able to parse properly.
PS: Earlier the above entry was as follows
<testcase name="workspace/inventory/group1">
<failure file="workspace/inventory/group1" line="94" message="[E201] Trailing whitespace" type="Ansible Lint">[E201] Trailing whitespace</failure>