I'm running spring-roo-1.2.1.BUILD-SNAPSHOT [rev 6df140d] in development mode. Sometimes (eg, at startup, but I've seen it after running for a while as well) the following message shows up:

Code:
[Spring Roo Process Manager Background Polling Thread] The file doesn't exist
java.lang.IllegalArgumentException: The file doesn't exist
   at org.springframework.roo.support.util.Assert.isTrue(Assert.java:65)
   at org.springframework.roo.classpath.javaparser.JavaParserTypeResolutionService.getPackage(JavaParserTypeResolutionService.java:46)
   at org.springframework.roo.classpath.TypeLocationServiceImpl.getPhysicalTypeIdentifier(TypeLocationServiceImpl.java:159)
   at org.springframework.roo.classpath.DefaultPhysicalTypeMetadataProvider.onFileEvent(DefaultPhysicalTypeMetadataProvider.java:91)
   at org.springframework.roo.file.monitor.polling.PollingFileMonitorService.publish(PollingFileMonitorService.java:350)
   at org.springframework.roo.file.monitor.polling.PollingFileMonitorService.scanAll(PollingFileMonitorService.java:323)
   at org.springframework.roo.process.manager.internal.DefaultProcessManager.doTransactionally(DefaultProcessManager.java:181)
   at org.springframework.roo.process.manager.internal.DefaultProcessManager.backgroundPoll(DefaultProcessManager.java:128)
   at org.springframework.roo.process.manager.internal.DefaultProcessManager.timerBasedPoll(DefaultProcessManager.java:243)
   at org.springframework.roo.process.manager.internal.DefaultProcessManager$2.run(DefaultProcessManager.java:71)
   at java.lang.Thread.run(Thread.java:722)

Things seem to work fine regardless of the error message. How can I find out which file is missing or what's causing this message to appear ?