java.io.IOException: Not an NBM project in D:\sources\mercurial\main\core
        at org.netbeans.modules.apisupport.project.universe.ModuleList$1.run(ModuleList.java:161)
        at org.netbeans.modules.apisupport.project.universe.ModuleList$1.run(ModuleList.java:153)
        at org.openide.util.Mutex.readAccess(Mutex.java:291)
        at org.netbeans.modules.apisupport.project.universe.ModuleList.getModuleList(ModuleList.java:152)
        at org.netbeans.modules.apisupport.project.universe.ModuleList.getModuleList(ModuleList.java:136)
        at org.netbeans.modules.apisupport.project.universe.TestEntry.getNetBeansOrgPath(TestEntry.java:187)
        at org.netbeans.modules.apisupport.project.universe.TestEntry.getSrcDir(TestEntry.java:139)
        at org.netbeans.modules.apisupport.project.universe.TestEntry.getProject(TestEntry.java:207)
        at org.netbeans.modules.apisupport.project.queries.UpdateTrackingFileOwnerQuery.getOwner(UpdateTrackingFileOwnerQuery.java:110)
        at org.netbeans.modules.apisupport.project.queries.UpdateTrackingFileOwnerQuery.getOwner(UpdateTrackingFileOwnerQuery.java:72)
        at org.netbeans.api.project.FileOwnerQuery.getOwner(FileOwnerQuery.java:147)
        at org.netbeans.modules.java.project.JavadocForBinaryQueryImpl.findJavadoc(JavadocForBinaryQueryImpl.java:67)
        at org.netbeans.api.java.queries.JavadocForBinaryQuery.findJavadoc(JavadocForBinaryQuery.java:85)
        at org.netbeans.modules.javadoc.search.JavadocRegistry.readRoots(JavadocRegistry.java:172)
        at org.netbeans.modules.javadoc.search.JavadocRegistry.getDocRoots(JavadocRegistry.java:127)
        at org.netbeans.modules.javadoc.search.IndexBuilder.refreshIndex(IndexBuilder.java:194)
        at org.netbeans.modules.javadoc.search.IndexBuilder.run(IndexBuilder.java:122)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:561)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:986)