TestRangeWithConcurrentDelMuts fails with forestdb "Assertion `pos < file->pos.val' failed"

TestRangeWithConcurrentDelMuts fails with "Assertion "pos < file->pos.val
Test Actions:
Insert 1000 docs into bucket
Create secondary index_company (creates 3 kv stores main, back and meta via indexer and insertes 1000 docs into first 2)
Spawn 2 threads..
Thread 1: Add 1000 docs per second into bucket (adds new mutations in 3 kv stores with point query on 2nd)
Thread 2: Range scan on index_company (initiates iterator and does iteratot_next operations)
----- wait for completion for 2 minutes----
Add 30K documents into same bucket
Spawn 3 threads...
Thread 1: Delete documents from bucket (causes point query on 2nd kv store and fdb_del on first)
Thread 2: Range query on index_company (iterator calls on 1st kv store)
Thread 3: Insert new documents into bucket (causes fdb_set and fdb_snapshot_open on first 2 kv stores)

Setup:

export GOTRACEBACK=crash
ulimit -c unlimited
sudo bash c "echo /tmp/core%e.$TS > /proc/sys/kernel/core_pattern"

(Setup local couchbase with 2 nodes and 1024 VBs)
make dataclean
COUCHBASE_NUM_VBUCKETS=1024 ./cluster_run --nodes=2

(Connect the two nodes)
./cluster_connect -n2 -s 3072 -T n0:kv,n1:kv+index

Test:
cd indexing/secondary/tests/largedatatests
go test -v -timeout 4000s

=== RUN TestRangeWithConcurrentDelMuts
2015/03/27 13:57:50 In TestRangeWithConcurrentDelMuts()
2015/03/27 13:57:50 Generating JSON docs
2015/03/27 13:57:54 Setting initial JSON docs in KV
2015/03/27 13:58:12 Creating a 2i
2015/03/27 13:58:13 Index found: index_company
2015/03/27 13:58:13 CreateDocs:: Delete mutations
2015/03/27 13:58:13 In Range Scan
— FAIL: TestRangeWithConcurrentDelMuts (142.95 seconds)