#0  malloc_consolidate (av=0x7f33c8277620 <main_arena>) at malloc.c:4240
#1  malloc_consolidate (av=0x7f33c8277620 <main_arena>) at malloc.c:4192
#2  0x00007f33c7f537d3 in _int_malloc (av=0x7f33c8277620 <main_arena>, 
    bytes=1174) at malloc.c:3532
#3  0x00007f33c7f575b5 in __libc_calloc (n=<optimized out>, 
    elem_size=<optimized out>) at malloc.c:3274
#4  0x00007f33c8926c3e in _dl_new_object (
    realname=0xcc46c0 "/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.3/libgcc_s.so.1", 
    libname=0x7f33c803ba8c "libgcc_s.so.1", type=2, loader=0x0, 
    mode=-1879048191, nsid=0) at dl-object.c:77
#5  0x00007f33c8922376 in _dl_map_object_from_fd (
    name=0x7f33c803ba8c "libgcc_s.so.1", fd=4, fbp=0x7ffff4b5c0f0, 
    realname=0xcc46c0 "/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.3/libgcc_s.so.1", 
    loader=0x0, l_type=2, mode=-1879048191, stack_endp=0x7ffff4b5c440, nsid=0)
    at dl-load.c:1051
#6  0x00007f33c89241c2 in _dl_map_object (loader=0x0, 
    name=0x7f33c803ba8c "libgcc_s.so.1", type=2, trace_mode=0, 
    mode=<optimized out>, nsid=<optimized out>) at dl-load.c:2344
#7  0x00007f33c892e52d in dl_open_worker (a=0x7ffff4b5c680) at dl-open.c:225
#8  0x00007f33c892a336 in _dl_catch_error (objname=0x7ffff4b5c6c8, 
    errstring=0x7ffff4b5c6d0, mallocedp=0x7ffff4b5c6df, 
    operate=0x7f33c892e400 <dl_open_worker>, args=0x7ffff4b5c680)
    at dl-error.c:178
#9  0x00007f33c892dfba in _dl_open (file=0x7f33c803ba8c "libgcc_s.so.1", 
    mode=-2147483647, caller_dlopen=0x7f33c7fd1255 <init+21>, nsid=-2, 
    argc=2, argv=<optimized out>, env=0xcbce20) at dl-open.c:639
#10 0x00007f33c7ff5c32 in do_dlopen (ptr=0x7ffff4b5c8b0) at dl-libc.c:89
#11 0x00007f33c892a336 in _dl_catch_error (objname=0x7ffff4b5c888, 
    errstring=0x7ffff4b5c890, mallocedp=0x7ffff4b5c89f, 
    operate=0x7f33c7ff5bf0 <do_dlopen>, args=0x7ffff4b5c8b0) at dl-error.c:178
#12 0x00007f33c7ff5ccf in dlerror_run (operate=<optimized out>, 
    args=<optimized out>) at dl-libc.c:48
#13 0x00007f33c7ff5d41 in __GI___libc_dlopen_mode (name=<optimized out>, 
    mode=<optimized out>) at dl-libc.c:165
#14 0x00007f33c7fd1255 in init () at ../sysdeps/x86_64/../ia64/backtrace.c:53
#15 0x00007f33c7fd139d in __GI___backtrace (array=<optimized out>, size=64)
    at ../sysdeps/x86_64/../ia64/backtrace.c:104
#16 0x00007f33c7f4c6bf in __libc_message (do_abort=2, 
    fmt=0x7f33c80400c8 "*** glibc detected *** %s: %s: 0x%s ***\n")
    at ../sysdeps/unix/sysv/linux/libc_fatal.c:178
#17 0x00007f33c7f52426 in malloc_printerr (action=3, 
    str=0x7f33c80402b8 "double free or corruption (fasttop)", 
    ptr=<optimized out>) at malloc.c:5007
#18 0x0000000000470b7e in read_builtin (list=0x0) at ./read.def:696
#19 0x000000000042ba73 in execute_builtin (builtin=0x46f800 <read_builtin>, 
    flags=<optimized out>, subshell=<optimized out>, words=<optimized out>)
    at execute_cmd.c:4113
#20 0x000000000042f2e5 in execute_builtin_or_function (flags=8, 
    fds_to_close=0xcc3a80, redirects=<optimized out>, var=0x0, 
    builtin=0x46f800 <read_builtin>, words=0xcbfd70) at execute_cmd.c:4538
#21 execute_simple_command (fds_to_close=<optimized out>, async=0, 
    pipe_out=-1, pipe_in=-1, simple_command=0x0) at execute_cmd.c:3948
#22 execute_command_internal (command=0xcc23c0, asynchronous=<optimized out>, 
    pipe_in=<optimized out>, pipe_out=<optimized out>, 
    fds_to_close=<optimized out>) at execute_cmd.c:735
#23 0x0000000000430dfe in execute_command (command=0xcc23c0)
    at execute_cmd.c:382
#24 0x000000000043125d in execute_while_or_until (while_command=0xcc3980, 
    type=0) at execute_cmd.c:3184
#25 0x000000000042d6fe in execute_while_command (
    while_command=<optimized out>) at execute_cmd.c:3152
#26 execute_command_internal (command=0xcc39a0, asynchronous=<optimized out>, 
    pipe_in=-1, pipe_out=-1, fds_to_close=0xcc39d0) at execute_cmd.c:831
#27 0x0000000000430dfe in execute_command (command=0xcc39a0)
    at execute_cmd.c:382
#28 0x000000000041ba8d in reader_loop () at eval.c:152
#29 0x000000000041a3cb in main (argc=2, argv=0x7ffff4b5da68, 
    env=0x7ffff4b5da80) at shell.c:749
quit