#0  UNLINK_SMALL_FREE (block=0xffffffff) at smalloc.c:1055
1055        const word_t bsize = block[M_SIZE] & M_MASK;
(gdb) bt
#0  UNLINK_SMALL_FREE (block=0xffffffff) at smalloc.c:1055
#1  0x080f5081 in mem_alloc (size=96) at smalloc.c:1527
#2  0x080f6a58 in xalloc_traced (size=86, malloc_trace_file=0x81193f3 "strfuns.c", malloc_trace_line=123) at xalloc.c:516
#3  0x080e9f01 in strbuf_grow (buf=0xbfffe200, len=22) at strfuns.c:123
#4  0x080e8bac in strbuf_add (buf=0xbfffe200, text=0xbfffd150 "No program to trace.\n") at strfuns.c:152
#5  0x080e8cc1 in strbuf_addf (buf=0x18, format=0x18 <Address 0x18 out of bounds>) at strfuns.c:226
#6  0x0809886b in collect_trace (sbuf=0xbfffe200, rvec=0x0) at interpret.c:18142
#7  0x0809893c in dump_trace (how=1, rvec=0x18) at interpret.c:18435
#8  0x080dfd44 in fatal (fmt=0x811b02c "mem_free: block %p magic match failed: size %lu, expected %lx, found %lx\n")
    at simulate.c:621
#9  0x080f5275 in sfree (ptr=0xffffffff) at smalloc.c:1821
#10 0x080f52ac in mem_free (ptr=0x829fd18) at smalloc.c:1854
#11 0x080f768f in free (ptr=0x829fd2c) at xalloc.c:1226
#12 0x402658c4 in gcry_free () from /usr/lib/libgcrypt.so.11
#13 0x0829fd2c in ?? ()
#14 0x402b856c in ?? () from /usr/lib/libgcrypt.so.11
#15 0x0829f7d0 in ?? ()
#16 0x402a0913 in gcry_mpi_sub () from /usr/lib/libgcrypt.so.11
#17 0x4cd72d6d in ?? ()
#18 0x0829fdb8 in ?? ()
#19 0x0829f7d0 in ?? ()
#20 0x402a0b8d in gcry_mpi_test_bit () from /usr/lib/libgcrypt.so.11
#21 0x402a6edf in gcry_mpi_aprint () from /usr/lib/libgcrypt.so.11
#22 0x00000011 in ?? ()
#23 0x0829fe74 in ?? ()
#24 0x0829ff00 in ?? ()
#25 0x4cd72d6d in ?? ()
#26 0x4000a670 in _dl_rtld_di_serinfo () from /lib/ld-linux.so.2
#27 0x402a24bc in gcry_mpi_gcd () from /usr/lib/libgcrypt.so.11
#28 0x00000080 in ?? ()
#29 0x0829ff30 in ?? ()
#30 0x00000001 in ?? ()
#31 0x00000001 in ?? ()
#32 0x0829fbe4 in ?? ()