(gdb) bt
#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
#1  0x00007ffff60a7af3 in __pthread_kill_internal (threadid=<optimized out>, signo=6) at pthread_kill.c:89
#2  0x00007ffff604d1a0 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#3  0x00007ffff60345fe in __GI_abort () at abort.c:77
#4  0x00007ffff629a41f in std::__glibcxx_assert_fail (file=<optimized out>, line=<optimized out>, function=<optimized out>, condition=<optimized out>)
    at /usr/src/debug/gcc/gcc/libstdc++-v3/src/c++11/assert_fail.cc:41
#5  0x0000555555d0ca6c in std::vector<char, std::allocator<char> >::operator[] (this=0x7fffb8524890, __n=0) at /usr/include/c++/15.2.1/bits/stl_vector.h:1282
#6  0x0000555555e663d7 in binarystream::output::blob_implicit (this=0x7fffd1ffb6b0, blob=std::vector of length 0, capacity 0) at binarystream.cpp:128
#7  0x0000555555ce8c69 in operator() (__closure=0x7fffd1ffb810, s=...) at moviefile-binary.cpp:117
#8  0x0000555555cf8bc7 in std::__invoke_impl<void, moviefile::binary_io(int, rrdata_set&, bool)::<lambda(binarystream::output&)>&, binarystream::output&>(std::__invoke_other, struct {...} &)
    (__f=...) at /usr/include/c++/15.2.1/bits/invoke.h:63
#9  0x0000555555cf438e in std::__invoke_r<void, moviefile::binary_io(int, rrdata_set&, bool)::<lambda(binarystream::output&)>&, binarystream::output&>(struct {...} &) (__fn=...)
    at /usr/include/c++/15.2.1/bits/invoke.h:152
#10 0x0000555555cf04e8 in std::_Function_handler<void(binarystream::output&), moviefile::binary_io(int, rrdata_set&, bool)::<lambda(binarystream::output&)> >::_M_invoke(const std::_Any_data &, binarystream::output &) (__functor=..., __args#0=...) at /usr/include/c++/15.2.1/bits/std_function.h:292
#11 0x0000555555e67577 in std::function<void(binarystream::output&)>::operator() (this=0x7fffd1ffb810, __args#0=...) at /usr/include/c++/15.2.1/bits/std_function.h:593
#12 0x0000555555e664b5 in binarystream::output::extension (this=0x7fffd1ffb7a0, tag=4125162199, fn=..., even_empty=false) at binarystream.cpp:146
#13 0x0000555555ce9509 in moviefile::binary_io (this=0x7fffb8523d30, _stream=21, rrd=..., as_state=true) at moviefile-binary.cpp:116
#14 0x0000555555d0359e in moviefile::save (this=0x7fffb8523d30, movie="/home/tod/emu/lsnes/projects/smw-research-12--9.lss", compression=7, binary=true, rrd=..., as_state=true)
    at moviefile.cpp:218
#15 0x0000555555cdd67f in do_save_state (filename="$SLOT:12", binary=1) at moviedata.cpp:249
#16 0x0000555555ca7130 in (anonymous namespace)::handle_saves () at mainloop.cpp:836
#17 0x0000555555ca78dc in main_loop (rom=..., initial=..., load_has_to_succeed=false) at mainloop.cpp:948
#18 0x00005555562a0eab in (anonymous namespace)::emulator_main (_args=0x5555576fb8b0) at mainwindow.cpp:628
#19 0x00005555562b855f in std::__invoke_impl<void*, void* (*)(void*), (anonymous namespace)::emu_args*> (__f=@0x55555764ddf0: 0x5555562a0dbf <(anonymous namespace)::emulator_main(void*)>)
    at /usr/include/c++/15.2.1/bits/invoke.h:63
#20 0x00005555562b84f6 in std::__invoke<void* (*)(void*), (anonymous namespace)::emu_args*> (__fn=@0x55555764ddf0: 0x5555562a0dbf <(anonymous namespace)::emulator_main(void*)>)
    at /usr/include/c++/15.2.1/bits/invoke.h:98
#21 0x00005555562b8479 in std::thread::_Invoker<std::tuple<void* (*)(void*), (anonymous namespace)::emu_args*> >::_M_invoke<0, 1> (this=0x55555764dde8)
    at /usr/include/c++/15.2.1/bits/std_thread.h:303
#22 0x00005555562b8434 in std::thread::_Invoker<std::tuple<void* (*)(void*), (anonymous namespace)::emu_args*> >::operator() (this=0x55555764dde8)
    at /usr/include/c++/15.2.1/bits/std_thread.h:310
#23 0x00005555562b8418 in std::thread::_State_impl<std::thread::_Invoker<std::tuple<void* (*)(void*), (anonymous namespace)::emu_args*> > >::_M_run (this=0x55555764dde0)
    at /usr/include/c++/15.2.1/bits/std_thread.h:255
#24 0x00007ffff62e55a4 in std::execute_native_thread_routine (__p=0x55555764dde0) at /usr/src/debug/gcc/gcc/libstdc++-v3/src/c++11/thread.cc:104
#25 0x00007ffff60a597a in start_thread (arg=<optimized out>) at pthread_create.c:454
#26 0x00007ffff61292bc in __GI___clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78
(gdb)