Lock obtain timed out error

We keep getting the following error over and over again.
At one stage we have a build that is running for 2000+ minutes where it normally would only take 50 minutes to run.

Build Babylon - Trunk: Could not save the build results (Occurrences 1)
(java.io.IOException: Lock obtain timed out: Lock@/tmp/lucene-ed82f3d1b9a2ff1733816749ce5d18d1-write.lock)
Strack Trace

java.io.IOException: Lock obtain timed out: Lock@/tmp/lucene-ed82f3d1b9a2ff1733816749ce5d18d1-write.lock
at org.apache.lucene.store.Lock.obtain(Lock.java:58)
at org.apache.lucene.index.IndexWriter.(IndexWriter.java:255)
at org.apache.lucene.index.IndexWriter.(IndexWriter.java:225)
at com.atlassian.bamboo.index.IndexConnectionManager.getWriter(IndexConnectionManager.java:104)
at com.atlassian.bamboo.index.IndexConnectionManager.index(IndexConnectionManager.java:75)
at com.atlassian.bamboo.index.DefaultBuildResultsIndexer.indexBuildResultKeepConnection(DefaultBuildResultsIndexer.java:146)
at com.atlassian.bamboo.index.DefaultBuildResultsIndexer.indexBuildResult(DefaultBuildResultsIndexer.java:90)
at com.atlassian.bamboo.build.pipeline.tasks.SaveBuildTask.call(SaveBuildTask.java:74)
at edu.emory.mathcs.backport.java.util.concurrent.FutureTask.run(FutureTask.java:176)
at edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:987)
at edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:528)
at edu.emory.mathcs.backport.java.util.concurrent.helpers.ThreadHelpers$1.run(ThreadHelpers.java:34)
at java.lang.Thread.run(Thread.java:595)