Buildbot-couchapp is a project mainly written in JavaScript, it's free.
A CouchApp that indexes buildbot test results
A CouchApp that indexes BuildBot builds
Get your BuildBot build slaves to fire a document like below for each unit test that fails.
{ "test_name": test_name, "builder": builder, "timestamp": timestamp, "bld_id": build_id, "step": step, "reason": reason }