check fails on Fedora 23

fails on assert

Program terminated with signal SIGABRT, Aborted.
#0  0x00007f3e1dfe5a98 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:55
55      return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);
(gdb) bt
#0  0x00007f3e1dfe5a98 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:55
#1  0x00007f3e1dfe769a in __GI_abort () at abort.c:89
#2  0x00000000007c5401 in ExceptionalCondition (conditionName=conditionName@entry=0x935157 "!(compareResult < 0)",
    errorType=errorType@entry=0x802217 "FailedAssertion", fileName=fileName@entry=0x935147 "nodeMergejoin.c",
    lineNumber=lineNumber@entry=942) at assert.c:54
#3  0x00000000005eba9f in ExecMergeJoin (node=node@entry=0x175f120) at nodeMergejoin.c:942
#4  0x00000000005d3958 in ExecProcNode (node=node@entry=0x175f120) at execProcnode.c:480
#5  0x00000000005cfe87 in ExecutePlan (dest=0x177d1e0, direction=<optimized out>, numberTuples=0, sendTuples=<optimized out>,
    operation=CMD_SELECT, planstate=0x175f120, estate=0x175f008) at execMain.c:1562
#6  standard_ExecutorRun (queryDesc=0x16c7e88, direction=<optimized out>, count=0) at execMain.c:342
#7  0x00000000006dd038 in PortalRunSelect (portal=portal@entry=0x16bed38, forward=forward@entry=1 '\001', count=0,
    count@entry=9223372036854775807, dest=dest@entry=0x177d1e0) at pquery.c:942
#8  0x00000000006de57e in PortalRun (portal=portal@entry=0x16bed38, count=count@entry=9223372036854775807,
    isTopLevel=isTopLevel@entry=1 '\001', dest=dest@entry=0x177d1e0, altdest=altdest@entry=0x177d1e0,
    completionTag=completionTag@entry=0x7ffe4f8236f0 "") at pquery.c:786
#9  0x00000000006db29b in exec_simple_query (
    query_string=0x1715318 "SELECT p1.oid, p1.proname, p2.oid, p2.proname\nFROM pg_proc AS p1, pg_proc AS p2\nWHERE p1.oid < p2.oid AND\n    p1.prosrc = p2.prosrc AND\n    p1.prolang = 12 AND p2.prolang = 12 AND\n    (p1.proisagg = f"...) at postgres.c:1105
#10 PostgresMain (argc=<optimized out>, argv=argv@entry=0x16a57a0, dbname=0x16a5500 "regression", username=<optimized out>)
    at postgres.c:4033
#11 0x000000000046810f in BackendRun (port=0x16c5f50) at postmaster.c:4204
#12 BackendStartup (port=0x16c5f50) at postmaster.c:3880
#13 ServerLoop () at postmaster.c:1683
#14 0x000000000067e98b in PostmasterMain (argc=argc@entry=8, argv=argv@entry=0x16a45e0) at postmaster.c:1292
#15 0x0000000000469376 in main (argc=8, argv=0x16a45e0) at main.c:223

Linux yen 4.2.1-300.fc23.x86_64+debug #1 SMP Mon Sep 21 21:58:30 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
gcc (GCC) 5.1.1 20150618 (Red Hat 5.1.1-4)