I got the following error during eclipse startup:
eclipse.buildId=M20130204-1200 java.version=1.7.0_21 java.vendor=Oracle Corporation BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=de_DE Framework arguments: -product org.eclipse.epp.package.jee.product Command-line arguments: -os win32 -ws win32 -arch x86_64 -product org.eclipse.epp.package.jee.product Error Tue Jun 04 16:59:24 CEST 2013 An internal error occurred during: "Updating indexes". java.lang.OutOfMemoryError: Java heap space at org.apache.maven.index.updater.IndexDataReader.readUTF(IndexDataReader.java:144) at org.apache.maven.index.updater.IndexDataReader.readField(IndexDataReader.java:134) at org.apache.maven.index.updater.IndexDataReader.readDocument(IndexDataReader.java:108) at org.apache.maven.index.updater.IndexDataReader.readIndex(IndexDataReader.java:75) at org.apache.maven.index.updater.DefaultIndexUpdater.unpackIndexData(DefaultIndexUpdater.java:523) at org.apache.maven.index.updater.DefaultIndexUpdater.loadIndexDirectory(DefaultIndexUpdater.java:212) at org.apache.maven.index.updater.DefaultIndexUpdater.access$300(DefaultIndexUpdater.java:75) at org.apache.maven.index.updater.DefaultIndexUpdater$LuceneIndexAdaptor.setIndexFile(DefaultIndexUpdater.java:645) at org.apache.maven.index.updater.DefaultIndexUpdater.fetchAndUpdateIndex(DefaultIndexUpdater.java:829) at org.apache.maven.index.updater.DefaultIndexUpdater.fetchAndUpdateIndex(DefaultIndexUpdater.java:156) at org.eclipse.m2e.core.internal.index.nexus.NexusIndexManager.updateRemoteIndex(NexusIndexManager.java:1136) at org.eclipse.m2e.core.internal.index.nexus.NexusIndexManager.updateIndex(NexusIndexManager.java:1080) at org.eclipse.m2e.core.internal.index.nexus.NexusIndexManager$1.run(NexusIndexManager.java:657) at org.eclipse.m2e.core.internal.index.nexus.IndexUpdaterJob.run(IndexUpdaterJob.java:72) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)
To solve this just delete the .cache folder in your M2_REPO directory (default ~/.m2/repository/.cache)