2i functional test fails - TestScanWithConcurrentIndexOps

There is intermittent test failure on TestScanWithConcurrentIndexOps.

http://ci2i.northscale.in/gsi-fdb-08.04.2016-03.10.fail.html

forestdb is at ebd50c5, changes since last good build:
ebd50c5 Get rid of an unused function: sb_bmp_is_active_block()

assertion failed [rsize && rsize <= trie->chunksize] at /opt/build/forestdb/src/hbtrie.cc:84 ((nil) != 0x7f8fc9c1e4a0)
Called from:
/opt/couchbase/bin/../lib/libforestdb.so() [0x7f902f919faa]
/opt/couchbase/bin/../lib/libforestdb.so() [0x7f902f8f6d37]
/opt/couchbase/bin/../lib/libforestdb.so() [0x7f902f8f92d9]
/opt/couchbase/bin/../lib/libforestdb.so() [0x7f902f8f8912]
/opt/couchbase/bin/../lib/libforestdb.so() [0x7f902f8f9579]
/opt/couchbase/bin/../lib/libforestdb.so() [0x7f902f8fea70]
/opt/couchbase/bin/../lib/libforestdb.so(fdb_iterator_next+0x65) [0x7f902f9023b2]
/opt/couchbase/bin/indexer(_cgo_ea7381d1a5e0_Cfunc_fdb_iterator_next+0x2c) [0xc74dde]
/opt/couchbase/bin/indexer() [0x4631e0]