.
Thread 1 (LWP 14047):
#0  0x00007efffb441f77 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
        resultvar = 0
        pid = 14047
        selftid = 14047
#1  0x00007efffb4455e8 in __GI_abort () at abort.c:90
        save_stage = 2
        act = {__sigaction_handler = {sa_handler = 0x7efffb58ea3d, sa_sigaction = 0x7efffb58ea3d}, sa_mask = {__val = {3, 140735301463388, 4, 139637898664308, 1, 139637898675336, 3, 140735301463364, 12, 139637898675340, 2, 139637898675340, 2, 140735301464176, 8, 140735301465936}}, sa_flags = 84, sa_restorer = 0x7}
        sigs = {__val = {32, 0 <repeats 15 times>}}
#2  0x00007efffb47f4fb in __libc_message (do_abort=do_abort@entry=2, fmt=fmt@entry=0x7efffb592740 "*** Error in `%s': %s: 0x%s ***\n") at ../sysdeps/unix/sysv/linux/libc_fatal.c:199
        ap = {{gp_offset = 40, fp_offset = 48, overflow_arg_area = 0x7fff7da6b760, reg_save_area = 0x7fff7da6b670}}
        ap_copy = {{gp_offset = 16, fp_offset = 48, overflow_arg_area = 0x7fff7da6b760, reg_save_area = 0x7fff7da6b670}}
        fd = 2
        on_2 = <optimized out>
        list = <optimized out>
        nlist = <optimized out>
        cp = <optimized out>
        written = <optimized out>
#3  0x00007efffb48b996 in malloc_printerr (ptr=0x7efffc4e7df0, str=0x7efffb5928b8 "free(): invalid next size (normal)", action=3) at malloc.c:4923
        buf = "00007efffc4e7df0"
        cp = <optimized out>
#4  _int_free (av=<optimized out>, p=0x7efffc4e7de0, have_lock=0) at malloc.c:3779
        size = <optimized out>
        fb = <optimized out>
        nextchunk = <optimized out>
        nextsize = <optimized out>
        nextinuse = <optimized out>
        prevsize = <optimized out>
        bck = <optimized out>
        fwd = <optimized out>
        errstr = <optimized out>
        locked = <optimized out>
        __func__ = "_int_free"
#5  0x00007efffba807b9 in std::basic_ostringstream<char, std::char_traits<char>, std::allocator<char> >::~basic_ostringstream() () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
No symbol table info available.
#6  0x00007efffbf1a05f in ?? ()
No symbol table info available.
#7  0x00007efffbf17591 in ?? ()
No symbol table info available.
#8  0x00007efffbf1604e in ?? ()
No symbol table info available.
#9  0x00007efffb42cde5 in __libc_start_main (main=0x7efffbf15d90, argc=1, ubp_av=0x7fff7da6da78, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff7da6da68) at libc-start.c:260
        result = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {0, -2963090627455066180, 139637908662830, 140735301474928, 0, 0, 2962813901424582588, 3107213553379729340}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x7efffbcfb910 <_dl_init+160>, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = -70272752}}}
        not_first_call = <optimized out>
#10 0x00007efffbf16a57 in ?? ()
No symbol table info available.