Through ruby driver. Client quits with error: assertion: 9001 socket exception

[conn6] Tue Jul 27 14:52:33 building new index on

for pubmed.author_score
[conn6] Tue Jul 27 14:52:33 Buildindex pubmed.author_score idxNo:0 { name: "id", ns: "pubmed.author_score", key:

}

Server stack:
Tue Jul 27 14:54:56 Got signal: 7 (Bus error).
Tue Jul 27 14:54:56 Backtrace:
0x7999a9 0x7fe599950af0 0x67ba09 0x6bb513 0x5f6577 0x5fc4f4 0x5fb270 0x5fb714 0x5fb152 0x5fb714 0x5fb152 0x5fb714 0x6b392c 0x6bc0c2 0x6bd37a 0x69db5e 0x6a13cc 0x79a62d 0x7ae4a0 0x7fe59a4549ca
./mongod(_ZN5mongo10abruptQuitEi+0x399) [0x7999a9]
/lib/libc.so.6(+0x33af0) [0x7fe599950af0]
./mongod(_ZN5mongo16NamespaceDetails5allocEPKciRNS_7DiskLocE+0x159) [0x67ba09]
./mongod(_ZN5mongo11DataFileMgr6insertEPKcPKvibRKNS_11BSONElementEb+0x463) [0x6bb513]
./mongod(_ZN5mongo11BtreeBucket9addBucketERNS_12IndexDetailsE+0x67) [0x5f6577]
./mongod(_ZN5mongo11BtreeBucket10insertHereENS_7DiskLocEiS1_RKNS_7BSONObjERKNS_8OrderingES1_S1_RNS_12IndexDetailsE+0x5e4) [0x5fc4f4]
./mongod(_ZN5mongo11BtreeBucket7_insertENS_7DiskLocES1_RKNS_7BSONObjERKNS_8OrderingEbS1_S1_RNS_12IndexDetailsE+0x2a0) [0x5fb270]
./mongod(_ZN5mongo11BtreeBucket9bt_insertENS_7DiskLocES1_RKNS_7BSONObjERKNS_8OrderingEbRNS_12IndexDetailsEb+0xc4) [0x5fb714]
./mongod(_ZN5mongo11BtreeBucket7_insertENS_7DiskLocES1_RKNS_7BSONObjERKNS_8OrderingEbS1_S1_RNS_12IndexDetailsE+0x182) [0x5fb152]
./mongod(_ZN5mongo11BtreeBucket9bt_insertENS_7DiskLocES1_RKNS_7BSONObjERKNS_8OrderingEbRNS_12IndexDetailsEb+0xc4) [0x5fb714]
./mongod(_ZN5mongo11BtreeBucket7_insertENS_7DiskLocES1_RKNS_7BSONObjERKNS_8OrderingEbS1_S1_RNS_12IndexDetailsE+0x182) [0x5fb152]
./mongod(_ZN5mongo11BtreeBucket9bt_insertENS_7DiskLocES1_RKNS_7BSONObjERKNS_8OrderingEbRNS_12IndexDetailsEb+0xc4) [0x5fb714]
./mongod() [0x6b392c]
./mongod(_ZN5mongo11DataFileMgr6insertEPKcPKvibRKNS_11BSONElementEb+0x1012) [0x6bc0c2]
./mongod(_ZN5mongo11DataFileMgr16insertWithObjModEPKcRNS_7BSONObjEb+0x5a) [0x6bd37a]
./mongod(_ZN5mongo14receivedInsertERNS_7MessageERNS_5CurOpE+0x33e) [0x69db5e]
./mongod(_ZN5mongo16assembleResponseERNS_7MessageERNS_10DbResponseERKNS_8SockAddrE+0x147c) [0x6a13cc]
./mongod(_ZN5mongo10connThreadEv+0x30d) [0x79a62d]
./mongod(thread_proxy+0x80) [0x7ae4a0]
/lib/libpthread.so.0(+0x69ca) [0x7fe59a4549ca]
Tue Jul 27 14:54:56 dbexit:
[conn15] Tue Jul 27 14:54:56 shutdown: going to close listening sockets...
[conn15] Tue Jul 27 14:54:56 going to close listening socket: 5
[conn15] Tue Jul 27 14:54:56 going to close listening socket: 6
[conn15] Tue Jul 27 14:54:56 going to close listening socket: 7
[conn15] Tue Jul 27 14:54:56 going to close listening socket: 8
[conn15] Tue Jul 27 14:54:56 shutdown: going to flush oplog...
[conn15] Tue Jul 27 14:54:56 shutdown: going to close sockets...
[conn15] Tue Jul 27 14:54:56 shutdown: waiting for fs preallocator...
[conn15] Tue Jul 27 14:54:56 shutdown: closing all files...
Tue Jul 27 14:54:56 closeAllFiles() finished
[conn15] Tue Jul 27 14:54:56 shutdown: removing fs lock...
Tue Jul 27 14:54:56 dbexit: really exiting now
ERROR: Client::~Client _context should be NULL: conn

First attempt to create index failed in the following way:

[conn118] Tue Jul 27 14:39:35 Buildindex pubmed.author_score idxNo:1 { ns: "pubmed.author_score", name: "author_1_year_-1", key:

}
1923800/17532184 10%
3075300/17532184 17%
3085500/17532184 17%
Tue Jul 27 14:40:30 Got signal: 7 (Bus error).
Tue Jul 27 14:40:31 Backtrace:
0x7999a9 0x7f921ee4faf0 0x4c62f3 0x5919d0 0x592f5a 0x6b8e72 0x6ba403 0x6bb935 0x6bd37a 0x69db5e 0x6a13cc 0x79a62d 0x7ae4a0 0x7f921f9539ca 0x7f921ef026fd
./mongod(_ZN5mongo10abruptQuitEi+0x399) [0x7999a9]
/lib/libc.so.6(+0x33af0) [0x7f921ee4faf0]
./mongod(_ZNK5mongo7BSONObj21getFieldDottedOrArrayERPKc+0xd3) [0x4c62f3]
./mongod(_ZNK5mongo9IndexSpec8_getKeysESt6vectorIPKcSaIS3_EES1_INS_11BSONElementESaIS6_EERKNS_7BSONObjERSt3setIS9_NS_22BSONObjCmpDefaultOrderESaIS9_EE+0x80) [0x5919d0]
./mongod(_ZNK5mongo9IndexSpec7getKeysERKNS_7BSONObjERSt3setIS1_NS_22BSONObjCmpDefaultOrderESaIS1_EE+0x2ea) [0x592f5a]
./mongod(_ZN5mongo14fastBuildIndexEPKcPNS_16NamespaceDetailsERNS_12IndexDetailsEi+0x562) [0x6b8e72]
./mongod() [0x6ba403]
./mongod(_ZN5mongo11DataFileMgr6insertEPKcPKvibRKNS_11BSONElementEb+0x885) [0x6bb935]
./mongod(_ZN5mongo11DataFileMgr16insertWithObjModEPKcRNS_7BSONObjEb+0x5a) [0x6bd37a]
./mongod(_ZN5mongo14receivedInsertERNS_7MessageERNS_5CurOpE+0x33e) [0x69db5e]
./mongod(_ZN5mongo16assembleResponseERNS_7MessageERNS_10DbResponseERKNS_8SockAddrE+0x147c) [0x6a13cc]
./mongod(_ZN5mongo10connThreadEv+0x30d) [0x79a62d]
./mongod(thread_proxy+0x80) [0x7ae4a0]
/lib/libpthread.so.0(+0x69ca) [0x7f921f9539ca]
/lib/libc.so.6(clone+0x6d) [0x7f921ef026fd]
Tue Jul 27 14:40:31 dbexit:
[conn118] Tue Jul 27 14:40:31 shutdown: going to close listening sockets...
[conn118] Tue Jul 27 14:40:31 going to close listening socket: 5
[conn118] Tue Jul 27 14:40:31 going to close listening socket: 6
[conn118] Tue Jul 27 14:40:31 going to close listening socket: 7
[conn118] Tue Jul 27 14:40:31 going to close listening socket: 8
[conn118] Tue Jul 27 14:40:31 shutdown: going to flush oplog...
[conn118] Tue Jul 27 14:40:31 shutdown: going to close sockets...
[conn118] Tue Jul 27 14:40:31 shutdown: waiting for fs preallocator...
[conn118] Tue Jul 27 14:40:31 shutdown: closing all files...
Tue Jul 27 14:40:33 closeAllFiles() finished
[conn118] Tue Jul 27 14:40:33 shutdown: removing fs lock...
Tue Jul 27 14:40:33 dbexit: really exiting now
ERROR: Client::~Client _context should be NULL: conn