Running the tests on a Gentoo x86_64 box for MariaDB 5.3.1.
I noticed that the oqgraph.basic and oqgraph.binlog tests crashed.
They both fail on INSERT with the same backtrace.

Logs:
oqgraph.binlog [ fail ]
Test ended at 2011-09-22 10:04:01

CURRENT_TEST: oqgraph.binlog
mysqltest: At line 21: query 'insert into graph(origid, destid) values (1,3), (3,1)' failed: 2013: Lost connection to MySQL server during query
The result from queries just before the failure was:
drop table if exists graph;
CREATE TABLE graph (
latch SMALLINT UNSIGNED NULL,
origid BIGINT UNSIGNED NULL,
destid BIGINT UNSIGNED NULL,
weight DOUBLE NULL,
seq BIGINT UNSIGNED NULL,
linkid BIGINT UNSIGNED NULL,
KEY (latch, origid, destid) USING HASH,
KEY (latch, destid, origid) USING HASH
) ENGINE=OQGRAPH;
SET binlog_format = row;
insert into graph(origid, destid) values (1,3), (3,1);

Server [mysqld.1 - pid: 13481, winpid: 13481, exit: 256] failed during test run
Server log from this test:
---------SERVER LOG START----------
110922 10:04:01 [Note] Plugin 'PBXT' is disabled.
110922 10:04:01 [Note] Plugin 'InnoDB' is disabled.
110922 10:04:01 [Warning] /var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/sql/mysqld: unknown variable 'loose-debug-sync-timeout=300'22 10:04:01 [Note] Event Scheduler: Loaded 0 events
110922 10:04:01 [Note] /var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/sql/mysqld: ready for connections.
Version: '5.3.1-MariaDB-beta-log' socket: '/var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/mysql-test/var-ns/tmp/mysqld.1.sock' port: 11260 Gentoo Linux mariadb-5.3.1_beta;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.
We will try our best to scrape up some info that will hopefully help diagnose
the problem, but since we have already crashed, something is definitely wrong
and this may fail.

key_buffer_size=0
read_buffer_size=131072
max_used_connections=1
max_threads=153
threads_connected=1
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 60714 K
bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x1815490
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
stack_bottom = 0x7f087c818ea8 thread_stack 0x48000
/var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/sql/mysqld(my_print_stacktrace+0x29) [0x95c675]
/var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/sql/mysqld(handle_segfault+0x43f) [0x5d2e55]
/lib64/libpthread.so.0(+0xea90) [0x7f087b6cda90]
/var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/mysql-test/var-ns/plugins/ha_oqgraph.so(open_query::oqgraph::insert_edge(unsigned long long, unsigned long long, double, bool)+0x2ac) [0x7f0871d2955a]
/var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/mysql-test/var-ns/plugins/ha_oqgraph.so(ha_oqgraph::write_row(unsigned char*)+0xcb) [0x7f0871d26375]
/var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/sql/mysqld(handler::ha_write_row(unsigned char*)+0x3a) [0x6cb874]
/var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/sql/mysqld(write_record(THD*, st_table*, st_copy_info*)+0x61) [0x656d5c]
/var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/sql/mysqld(mysql_insert(THD*, TABLE_LIST*, List<Item>&, List<List<Item> >&, List<Item>&, List<Item>&, enum_duplicates, bool)+0x8ac) [0x65bdaa]
/var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/sql/mysqld(mysql_execute_command(THD*)+0x18cf) [0x5dfe8e]
/var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/sql/mysqld(mysql_parse(THD*, char*, unsigned int, char const**)+0x28a) [0x5e3d87]
/var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/sql/mysqld(dispatch_command(enum_server_command, THD*, char*, unsigned int)+0xae6) [0x5e5570]
/var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/sql/mysqld(do_command(THD*)+0xde) [0x5e5f53]
/var/tmp/portage/dev-db/mariadb-5.3.1_beta/work/mysql/sql/mysqld(handle_one_connection+0x161) [0x5d90a7]
/lib64/libpthread.so.0(+0x6a7d) [0x7f087b6c5a7d]
/lib64/libc.so.6(clone+0x6d) [0x7f087ac93d7d]

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (0x1831078): insert into graph(origid, destid) values (1,3), (3,1)
Connection ID (thread ID): 2
Status: NOT_KILLED
Optimizer switch: index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=off,table_elimination=on

The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains
information that should help you find out what is causing the crash.
Writing a core file
---------SERVER LOG END------------