When JBDS 5.0.beta2 is closed, this error is written to stdout:

12:25:54.899 [Worker-11] ERROR o.e.m.c.i.i.nexus.NexusIndexManager - Unable to update index for central|http://repo1.maven.org/maven2
org.apache.lucene.index.CorruptIndexException: Unknown format version: -9
at org.apache.lucene.index.SegmentInfos.read(SegmentInfos.java:225) ~[lucene-core-2.4.1.jar:2.4.1 750176 - 2009-03-04 21:56:52]
at org.apache.lucene.index.DirectoryIndexReader$1.doBody(DirectoryIndexReader.java:95) ~[lucene-core-2.4.1.jar:2.4.1 750176 - 2009-03-04 21:56:52]
at org.apache.lucene.index.SegmentInfos$FindSegmentsFile.run(SegmentInfos.java:653) ~[lucene-core-2.4.1.jar:2.4.1 750176 - 2009-03-04 21:56:52]
at org.apache.lucene.index.DirectoryIndexReader.open(DirectoryIndexReader.java:115) ~[lucene-core-2.4.1.jar:2.4.1 750176 - 2009-03-04 21:56:52]
at org.apache.lucene.index.IndexReader.open(IndexReader.java:316) ~[lucene-core-2.4.1.jar:2.4.1 750176 - 2009-03-04 21:56:52]
at org.apache.lucene.index.IndexReader.open(IndexReader.java:227) ~[lucene-core-2.4.1.jar:2.4.1 750176 - 2009-03-04 21:56:52]
at org.apache.maven.index.updater.DefaultIndexUpdater.copyUpdatedDocuments(DefaultIndexUpdater.java:352) ~[indexer-core-3.1.0.jar:3.1.0]
at org.apache.maven.index.updater.DefaultIndexUpdater.unpackIndexArchive(DefaultIndexUpdater.java:288) ~[indexer-core-3.1.0.jar:3.1.0]
at org.apache.maven.index.updater.DefaultIndexUpdater.loadIndexDirectory(DefaultIndexUpdater.java:218) ~[indexer-core-3.1.0.jar:3.1.0]
at org.apache.maven.index.updater.DefaultIndexUpdater.access$300(DefaultIndexUpdater.java:75) ~[indexer-core-3.1.0.jar:3.1.0]
at org.apache.maven.index.updater.DefaultIndexUpdater$LuceneIndexAdaptor.setIndexFile(DefaultIndexUpdater.java:645) ~[indexer-core-3.1.0.jar:3.1.0]
at org.apache.maven.index.updater.DefaultIndexUpdater.fetchAndUpdateIndex(DefaultIndexUpdater.java:844) ~[indexer-core-3.1.0.jar:3.1.0]
at org.apache.maven.index.updater.DefaultIndexUpdater.fetchAndUpdateIndex(DefaultIndexUpdater.java:156) ~[indexer-core-3.1.0.jar:3.1.0]
at org.eclipse.m2e.core.internal.index.nexus.NexusIndexManager.updateRemoteIndex(NexusIndexManager.java:1137) [org.eclipse.m2e.core_1.0.200.20111228-1245.jar:na]
at org.eclipse.m2e.core.internal.index.nexus.NexusIndexManager.updateIndex(NexusIndexManager.java:1081) [org.eclipse.m2e.core_1.0.200.20111228-1245.jar:na]
at org.eclipse.m2e.core.internal.index.nexus.NexusIndexManager$1.run(NexusIndexManager.java:658) [org.eclipse.m2e.core_1.0.200.20111228-1245.jar:na]
at org.eclipse.m2e.core.internal.index.nexus.IndexUpdaterJob.run(IndexUpdaterJob.java:71) [org.eclipse.m2e.core_1.0.200.20111228-1245.jar:na]
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54) [org.eclipse.core.jobs_3.5.101.v20120113-1953.jar:na]