From this log you can see that first it finds exec file in my workspace and then says that this workspace does not exist. I'm confused.

Recording test results
[JaCoCo plugin] Collecting JaCoCo coverage data...
[JaCoCo plugin] */.exec;/classes;*/src/main/java; locations are configured
[JaCoCo plugin] Number of found exec files: 1
[JaCoCo plugin] Saving matched execfiles: /scratch/jenkins/workspace/reference/build/tmp/jacoco/jacoco.execERROR: Publisher hudson.plugins.jacoco.JacocoPublisher aborted due to exception
java.lang.IllegalStateException: basedir /scratch/jenkins/workspace/reference does not exist.
at org.apache.tools.ant.DirectoryScanner.scan(DirectoryScanner.java:879)
at hudson.plugins.jacoco.JacocoPublisher.resolveDirPaths(JacocoPublisher.java:116)
at hudson.plugins.jacoco.JacocoPublisher.perform(JacocoPublisher.java:181)
at hudson.tasks.BuildStepMonitor$3.perform(BuildStepMonitor.java:36)
at hudson.model.AbstractBuild$AbstractRunner.perform(AbstractBuild.java:720)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildSteps(AbstractBuild.java:695)
at hudson.model.Build$RunnerImpl.post2(Build.java:162)
at hudson.model.AbstractBuild$AbstractRunner.post(AbstractBuild.java:642)
at hudson.model.Run.run(Run.java:1463)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:239)
Recording fingerprints
Notifying upstream projects of job completion
Finished: FAILURE