Created attachment 136578 [details]
Messages.log with the exception thrown

The following exception is thrown when trying to touch a Maven RCP project which is in the background scanning stage:

java.lang.IllegalStateException: may not call Project.getLookup().lookup(...) inside org.netbeans.modules.maven.persistence.MavenPersistenceProvider registered under @ProjectServiceProvider
	at org.netbeans.modules.projectapi.LazyLookupProviders$1$1.safeToLoad(LazyLookupProviders.java:136)
	at org.netbeans.modules.projectapi.LazyLookupProviders$1$1.beforeLookup(LazyLookupProviders.java:92)
	at org.openide.util.lookup.ProxyLookup.beforeLookup(ProxyLookup.java:210)
	at org.openide.util.lookup.ProxyLookup$R.myBeforeLookup(ProxyLookup.java:653)
	at org.openide.util.lookup.ProxyLookup$R.beforeLookup(ProxyLookup.java:675)
	at org.openide.util.lookup.ProxyLookup$R.myBeforeLookup(ProxyLookup.java:662)
	at org.openide.util.lookup.ProxyLookup$R.beforeLookup(ProxyLookup.java:675)
	at org.openide.util.lookup.ExcludingLookup$R.beforeLookup(ExcludingLookup.java:328)
	at org.openide.util.lookup.ProxyLookup$R.myBeforeLookup(ProxyLookup.java:662)
	at org.openide.util.lookup.ProxyLookup$R.computeResult(ProxyLookup.java:550)
	at org.openide.util.lookup.ProxyLookup$R.allItems(ProxyLookup.java:534)
	at org.openide.util.lookup.ProxyLookup$R.allItems(ProxyLookup.java:529)
	at org.openide.util.lookup.SimpleProxyLookup$ProxyResult.updateLookup(SimpleProxyLookup.java:198)
	at org.openide.util.lookup.SimpleProxyLookup$ProxyResult.checkResult(SimpleProxyLookup.java:188)
	at org.openide.util.lookup.SimpleProxyLookup$ProxyResult.allInstances(SimpleProxyLookup.java:267)
	at org.openide.util.Lookup.lookupAll(Lookup.java:271)
	at org.netbeans.modules.maven.NbMavenProjectImpl.getSourceRoots(NbMavenProjectImpl.java:542)
	at org.netbeans.modules.maven.NbMavenProjectImpl.getResources(NbMavenProjectImpl.java:658)
	at org.netbeans.modules.maven.api.NbMavenProject.getResources(NbMavenProject.java:293)
	at org.netbeans.modules.maven.persistence.PersistenceLocationProviderImpl.findPersistenceXml(PersistenceLocationProviderImpl.java:167)
	at org.netbeans.modules.maven.persistence.PersistenceLocationProviderImpl.<init>(PersistenceLocationProviderImpl.java:85)
	at org.netbeans.modules.maven.persistence.MavenPersistenceProvider.<init>(MavenPersistenceProvider.java:85)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
	at org.netbeans.modules.projectapi.LazyLookupProviders.loadPSPInstance(LazyLookupProviders.java:167)
	at org.netbeans.modules.projectapi.LazyLookupProviders.access$000(LazyLookupProviders.java:73)
	at org.netbeans.modules.projectapi.LazyLookupProviders$1$1.beforeLookup(LazyLookupProviders.java:104)
	at org.openide.util.lookup.ProxyLookup.lookup(ProxyLookup.java:215)
	at org.openide.util.lookup.ProxyLookup.lookup(ProxyLookup.java:223)
	at org.openide.util.lookup.ExcludingLookup.lookup(ExcludingLookup.java:142)
	at org.openide.util.lookup.ProxyLookup.lookup(ProxyLookup.java:223)
	at org.openide.util.lookup.SimpleProxyLookup.lookup(SimpleProxyLookup.java:156)
	at org.netbeans.modules.j2ee.persistence.api.PersistenceLocation.getLocation(PersistenceLocation.java:71)
	at org.netbeans.modules.j2ee.persistence.indexing.CopyResourcesIndexer$Factory.scanStarted(CopyResourcesIndexer.java:106)
	at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doStartCustomIndexer(RepositoryUpdater.java:2334)
	at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.customIndexersScanStarted(RepositoryUpdater.java:2316)
	at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.scanStarted(RepositoryUpdater.java:2277)
	at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork.scanSource(RepositoryUpdater.java:5171)
	at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork.scanSources(RepositoryUpdater.java:4889)
	at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$RootsWork.getDone(RepositoryUpdater.java:4594)
	at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doTheWork(RepositoryUpdater.java:3194)
	at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task._run(RepositoryUpdater.java:5622)
	at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.access$4800(RepositoryUpdater.java:5288)
	at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3$1.run(RepositoryUpdater.java:5547)
	at org.netbeans.modules.parsing.impl.RunWhenScanFinishedSupport.performScan(RunWhenScanFinishedSupport.java:96)
	at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3.call(RepositoryUpdater.java:5543)
	at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3.call(RepositoryUpdater.java:5539)
	at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
	at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
	at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:74)
	at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.run(RepositoryUpdater.java:5539)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
	at java.util.concurrent.FutureTask.run(FutureTask.java:166)
	at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1432)
	at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2042)


Steps to reproduce:

1. Open a Maven RCP application.
2. Open another (large) Maven RCP application, check "Open required projects" option.
3. While "Background scanning" is in progress, touch a project in the Projects window. The IllegalStateException is thrown.