(gdb) backtrace
#0  0xb6d77bfc in __GI_raise (sig=6)
    at ../nptl/sysdeps/unix/sysv/linux/raise.c:67
#1  0xb6d7b97c in __GI_abort () at abort.c:92
#2  0xb6dafcf8 in __libc_message (do_abort=2, fmt=
    0xb6e618d0 "*** glibc detected *** %s: %s: 0x%s ***\n")
    at ../sysdeps/unix/sysv/linux/libc_fatal.c:189
#3  0xb6dba584 in malloc_printerr (action=3, str=
    0xb6e61af0 "double free or corruption (!prev)", ptr=<optimized out>)
    at malloc.c:6283
#4  0xb6dbee00 in __GI___libc_free (mem=<optimized out>) at malloc.c:3738
#5  0xb63061bc in deallocate (__p=0x2018198, this=<optimized out>)
    at /usr/include/c++/4.6/ext/new_allocator.h:98
#6  _M_deallocate (__p=0x2018198, this=<optimized out>, __n=<optimized out>)
    at /usr/include/c++/4.6/bits/stl_vector.h:156
#7  ~_Vector_base (this=0xbee7c59c, __in_chrg=<optimized out>)
    at /usr/include/c++/4.6/bits/stl_vector.h:142
#8  ~vector (this=0xbee7c59c, __in_chrg=<optimized out>)
    at /usr/include/c++/4.6/bits/stl_vector.h:350
#9  gr::filter::firdes::low_pass (gain=<optimized out>,
    sampling_freq=<optimized out>, cutoff_freq=0.45000000000000001,
    transition_width=<optimized out>, window_type=<optimized out>,
    beta=<optimized out>) at /home/pi/gnuradio/gr-filter/lib/firdes.cc:136
Python Exception <class 'gdb.error'> There is no member named ob_ival.:
#10 0xb3ac090c in _wrap_firdes_low_pass (args=, kwargs=<optimized out>)
    at /home/pi/gnuradio/build/gr-filter/swig/filter_swigPYTHON_wrap.cxx:5331
#11 0x0005c554 in PyCFunction_Call (func=0x17f0c88, arg=<optimized out>,
    kw=<optimized out>) at ../Objects/methodobject.c:85
#12 0x00168164 in ext_do_call (nk=2435396, na=<optimized out>,
    flags=<optimized out>, pp_stack=0xbee7c748, func=0x17f0c88)
    at ../Python/ceval.c:4331
#13 PyEval_EvalFrameEx (f=<optimized out>, throwflag=<optimized out>)
    at ../Python/ceval.c:2705
#14 0x0016a880 in PyEval_EvalCodeEx (co=0x14cef98, globals=<optimized out>,
    locals=<optimized out>, args=0x1670680, argcount=6, kws=0x2017e88,
    kwcount=0, defs=0x0, defcount=0, closure=0x0) at ../Python/ceval.c:3253
#15 0x00164404 in fast_function (nk=<optimized out>, na=6, n=6, pp_stack=
    0xbee7c850, func=0x17eaef0) at ../Python/ceval.c:4117
#16 call_function (oparg=<optimized out>, pp_stack=0xbee7c850)
    at ../Python/ceval.c:4042
#17 PyEval_EvalFrameEx (f=<optimized out>, throwflag=<optimized out>)
    at ../Python/ceval.c:2666
#18 0x001645e4 in fast_function (nk=<optimized out>, na=<optimized out>,
    n=<optimized out>, pp_stack=0xbee7c8f0, func=0x18f8ab0)
    at ../Python/ceval.c:4107
#19 call_function (oparg=<optimized out>, pp_stack=0xbee7c8f0)
    at ../Python/ceval.c:4042
#20 PyEval_EvalFrameEx (f=<optimized out>, throwflag=<optimized out>)
    at ../Python/ceval.c:2666
#21 0x0016a880 in PyEval_EvalCodeEx (co=0x1674380, globals=<optimized out>,
    locals=<optimized out>, args=0xb6abdbf0, argcount=6, kws=0x0, kwcount=0,
    defs=0x18e23fc, defcount=2, closure=0x0) at ../Python/ceval.c:3253
#22 0x0016b79c in function_call.14163 (func=0x18f8b30, arg=0x19b2650,
    kw=<optimized out>) at ../Objects/funcobject.c:526
#23 0x0005cc98 in PyObject_Call (func=0x18f8b30, arg=<optimized out>,
    kw=<optimized out>) at ../Objects/abstract.c:2529
#24 0x000658dc in instancemethod_call.7673 (func=0x18f8b30, arg=0x19b2650, kw=
    0x0) at ../Objects/classobject.c:2602
#25 0x0005cc98 in PyObject_Call (func=0x1943d78, arg=<optimized out>,
    kw=<optimized out>) at ../Objects/abstract.c:2529
#26 0x001644fc in do_call (nk=<optimized out>, na=6, pp_stack=0xbee7ccb0, func=
    0x1943d78) at ../Python/ceval.c:4239
#27 call_function (oparg=<optimized out>, pp_stack=0xbee7ccb0)
    at ../Python/ceval.c:4044
#28 PyEval_EvalFrameEx (f=<optimized out>, throwflag=<optimized out>)
    at ../Python/ceval.c:2666
#29 0x0016a880 in PyEval_EvalCodeEx (co=0x17629b0, globals=<optimized out>,
    locals=<optimized out>, args=0x190f4e8, argcount=1, kws=0x19390fc,
    kwcount=4, defs=0x18f3d34, defcount=2, closure=0x0)
    at ../Python/ceval.c:3253
#30 0x0016b918 in function_call.14163 (func=<optimized out>, arg=0x1a9a4d0,
    kw=<optimized out>) at ../Objects/funcobject.c:526
#31 0x0005cc98 in PyObject_Call (func=0x18f8bb0, arg=<optimized out>,
    kw=<optimized out>) at ../Objects/abstract.c:2529
#32 0x000658dc in instancemethod_call.7673 (func=0x18f8bb0, arg=0x1a9a4d0, kw=
    0x1a40390) at ../Objects/classobject.c:2602
#33 0x0005cc98 in PyObject_Call (func=0x1943968, arg=<optimized out>,
    kw=<optimized out>) at ../Objects/abstract.c:2529
#34 0x000645d8 in slot_tp_init.24734 (self=<optimized out>, args=0xb6ce3030,
    kwds=0x1a40390) at ../Objects/typeobject.c:5677
#35 0x0004b8cc in type_call.24392 (type=0x1917e70, args=0xb6ce3030, kwds=
    0x1a40390) at ../Objects/typeobject.c:737
#36 0x0005cc98 in PyObject_Call (func=0x1917e70, arg=<optimized out>,
    kw=<optimized out>) at ../Objects/abstract.c:2529
#37 0x001644fc in do_call (nk=<optimized out>, na=0, pp_stack=0xbee7d0b0, func=
    0x1917e70) at ../Python/ceval.c:4239
#38 call_function (oparg=<optimized out>, pp_stack=0xbee7d0b0)
    at ../Python/ceval.c:4044
#39 PyEval_EvalFrameEx (f=<optimized out>, throwflag=<optimized out>)
    at ../Python/ceval.c:2666
#40 0x0016a880 in PyEval_EvalCodeEx (co=0xb6c638d8, globals=<optimized out>,
    locals=<optimized out>, args=0xb6ce3a00, argcount=1, kws=0x0, kwcount=0,
    defs=0x0, defcount=0, closure=0x0) at ../Python/ceval.c:3253
#41 0x0016b79c in function_call.14163 (func=0x1962970, arg=0x1913c30,
    kw=<optimized out>) at ../Objects/funcobject.c:526
#42 0x0005cc98 in PyObject_Call (func=0x1962970, arg=<optimized out>,
    kw=<optimized out>) at ../Objects/abstract.c:2529
#43 0x000658dc in instancemethod_call.7673 (func=0x1962970, arg=0x1913c30, kw=
    0x0) at ../Objects/classobject.c:2602
#44 0x0005cc98 in PyObject_Call (func=0x1943940, arg=<optimized out>,
    kw=<optimized out>) at ../Objects/abstract.c:2529
#45 0x000645d8 in slot_tp_init.24734 (self=<optimized out>, args=0xb6ce3030,
    kwds=0x0) at ../Objects/typeobject.c:5677
#46 0x0004b8cc in type_call.24392 (type=0x19e0520, args=0xb6ce3030, kwds=0x0)
    at ../Objects/typeobject.c:737
#47 0x0005cc98 in PyObject_Call (func=0x19e0520, arg=<optimized out>,
    kw=<optimized out>) at ../Objects/abstract.c:2529
#48 0x001644fc in do_call (nk=<optimized out>, na=0, pp_stack=0xbee7d4b0, func=
    0x19e0520) at ../Python/ceval.c:4239
#49 call_function (oparg=<optimized out>, pp_stack=0xbee7d4b0)
    at ../Python/ceval.c:4044
#50 PyEval_EvalFrameEx (f=<optimized out>, throwflag=<optimized out>)
    at ../Python/ceval.c:2666
#51 0x0016a880 in PyEval_EvalCodeEx (co=0xb6c77cc8, globals=<optimized out>,
    locals=<optimized out>, args=0x2a5724, argcount=0, kws=0x0, kwcount=0,
    defs=0x0, defcount=0, closure=0x0) at ../Python/ceval.c:3253
#52 0x000e93a4 in PyEval_EvalCode (locals=0xbee7d698, globals=0xb6d15660, co=
    0xb6c77cc8) at ../Python/ceval.c:667
#53 run_mod (arena=0x871a20, flags=0xb6d15660, locals=0xbee7d698, globals=
    0xb6d15660, filename=<optimized out>, mod=0x8e12f8)
    at ../Python/pythonrun.c:1365
#54 PyRun_FileExFlags (fp=0x87b5c8, filename=<optimized out>,
    start=<optimized out>, globals=0xb6d15660, locals=0xb6d15660, closeit=1,
    flags=0xbee7d698) at ../Python/pythonrun.c:1351
#55 0x000e95f4 in PyRun_SimpleFileExFlags (fp=0x87b5c8, filename=
    0xbee7d92a "top_block.py", closeit=1, flags=0xbee7d698)
    at ../Python/pythonrun.c:943
#56 0x000eac18 in Py_Main (argc=<optimized out>, argv=<optimized out>)
    at ../Modules/main.c:639
#57 0xb6d6281c in __libc_start_main (main=0xbee7d814, argc=-1226350592, ubp_av=
    0xb6d6281c, init=<optimized out>, fini=0x1869b0 <__libc_csu_fini>,
    rtld_fini=0xb6f6a5a4, stack_end=0xbee7d814) at libc-start.c:228
#58 0x000208ec in _start ()