LOG:  database system was interrupted while in recovery at 2015-07-26 19:30:50 UTC
HINT:  This probably means that some data is corrupted and you will have to use the last backup for recovery.
LOG:  database system was not properly shut down; automatic recovery in progress
LOG:  redo starts at 0/172A828
LOG:  could not remove symbolic link "pg_tblspc/16386": No such file or directory
CONTEXT:  xlog redo Tablespace/DROP: 16386
TRAP: FailedAssertion("!(xldata->parentBlk == -1)", File: "/microsd/postgres/compiled-clean/../sources/src/backend/access/spgist/spgxlog.c", Line: 338)
LOG:  startup process (PID 2734) was terminated by signal 6: Aborted
LOG:  aborting startup due to startup process failure

(gdb) bt
#0  0xb6e028e6 in ?? () from /lib/arm-linux-gnueabihf/libc.so.6
#1  0xb6e10f0e in raise () from /lib/arm-linux-gnueabihf/libc.so.6
#2  0xb6e13766 in abort () from /lib/arm-linux-gnueabihf/libc.so.6
#3  0x002eef06 in ExceptionalCondition (conditionName=conditionName@entry=0x36693c "!(xldata->parentBlk == -1)", 
    errorType=errorType@entry=0x31e778 "FailedAssertion", 
    fileName=fileName@entry=0x3659b0 "/microsd/postgres/compiled-clean/../sources/src/backend/access/spgist/spgxlog.c", lineNumber=lineNumber@entry=338)
    at /microsd/postgres/compiled-clean/../sources/src/backend/utils/error/assert.c:54
#4  0x000b2d7c in spgRedoAddNode (record=0xb6ecf0ac) at /microsd/postgres/compiled-clean/../sources/src/backend/access/spgist/spgxlog.c:338
#5  spg_redo (record=0xb6ecf0ac) at /microsd/postgres/compiled-clean/../sources/src/backend/access/spgist/spgxlog.c:987
#6  0x000ce3f6 in StartupXLOG () at /microsd/postgres/compiled-clean/../sources/src/backend/access/transam/xlog.c:6803
#7  0x001f24e6 in StartupProcessMain () at /microsd/postgres/compiled-clean/../sources/src/backend/postmaster/startup.c:215
#8  0x000d8368 in AuxiliaryProcessMain (argc=argc@entry=2, argv=argv@entry=0xbef3d064)
    at /microsd/postgres/compiled-clean/../sources/src/backend/bootstrap/bootstrap.c:418
#9  0x001ef4da in StartChildProcess (type=-1091317660, type@entry=StartupProcess)
    at /microsd/postgres/compiled-clean/../sources/src/backend/postmaster/postmaster.c:5167
#10 0x001f20d4 in PostmasterMain (argc=5270948, argc@entry=4748240, argv=0x508d68, argv@entry=0x3766f8)
    at /microsd/postgres/compiled-clean/../sources/src/backend/postmaster/postmaster.c:1255
#11 0x0019c322 in main (argc=4748240, argv=0x3766f8) at /microsd/postgres/compiled-clean/../sources/src/backend/main/main.c:223
(gdb) f 4
#4  0x000b2d7c in spgRedoAddNode (record=0xb6ecf0ac) at /microsd/postgres/compiled-clean/../sources/src/backend/access/spgist/spgxlog.c:338
338                     Assert(xldata->parentBlk == -1);
(gdb) list
333             fillFakeState(&state, xldata->stateSrc);
334
335             if (!XLogRecHasBlockRef(record, 1))
336             {
337                     /* update in place */
338                     Assert(xldata->parentBlk == -1);
339                     if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
340                     {
341                             page = BufferGetPage(buffer);
342
(gdb) print xldata->parentBlk
$1 = 0 '\000'