gdb) bt 20
#0  0x00007f5ac5e2c067 in __GI_raise (sig=sig@entry=6)
    at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1  0x00007f5ac5e2d448 in __GI_abort () at abort.c:89
#2  0x00007f5ac69715ec in __gnu_cxx::__verbose_terminate_handler ()
    at /home/brain/gcc/libstdc++-v3/libsupc++/vterminate.cc:95
#3  0x00007f5ac697b9c6 in __cxxabiv1::__terminate(void (*)()) ()
    at /home/brain/gcc/libstdc++-v3/libsupc++/eh_terminate.cc:48
#4  0x00007f5ac697aaa9 in __cxa_call_terminate (ue_header=ue_header@entry=0x7f5a944a8370)
    at /home/brain/gcc/libstdc++-v3/libsupc++/eh_call.cc:54
#5  0x00007f5ac697b3e1 in __gxx_personality_v0 ()
    at /home/brain/gcc/libstdc++-v3/libsupc++/eh_personality.cc:685
#6  0x00007f5ac63cf1df in _Unwind_RaiseException_Phase2 ()
    at /home/brain/gcc/libgcc/unwind.inc:64
#7  0x00007f5ac63cf861 in _Unwind_RaiseException () at /home/brain/gcc/libgcc/unwind.inc:136
#8  0x00007f5ac697bcb7 in __cxxabiv1::__cxa_throw (obj=obj@entry=0x7f5a944a8390,
    tinfo=0x8b6be0 <typeinfo for std::system_error@@GLIBCXX_3.4.11>,
    tinfo@entry=0x7f5ac6c8e5f0 <typeinfo for std::system_error>,
    dest=0x40b060 <std::system_error::~system_error()@plt>,
    dest@entry=0x7f5ac69a4d90 <std::system_error::~system_error()>)
    at /home/brain/gcc/libstdc++-v3/libsupc++/eh_throw.cc:90
#9  0x00007f5ac697421a in std::__throw_system_error (__i=35)
    at /home/brain/gcc10/x86_64-pc-linux-gnu/libstdc++-v3/include/system_error:214
#10 0x000000000043ccf7 in std::__shared_mutex_pthread::lock (this=0x7ffe33bf6ab0)
    at /usr/local/include/c++/10.0.0/shared_mutex:190
#11 0x000000000043cdb2 in std::shared_mutex::lock (this=0x7ffe33bf6ab0)
    at /usr/local/include/c++/10.0.0/shared_mutex:415
#12 0x0000000000489299 in std::unique_lock<std::shared_mutex>::lock (this=0x7f5ac29e3380)
    at /usr/local/include/c++/10.0.0/bits/unique_lock.h:138
#13 0x0000000000467b89 in std::unique_lock<std::shared_mutex>::unique_lock (this=0x7f5ac29e3380,
    __m=...) at /usr/local/include/c++/10.0.0/bits/unique_lock.h:68
#14 0x00000000004429f5 in aegis::core::remove_guild (this=0x7ffe33bf6370, guild_id=...)
    at /usr/local/include/aegis/impl/core.cpp:389
#15 0x000000000044bfe8 in aegis::core::ws_guild_delete (this=0x7ffe33bf6370, result=...,
    _shard=0xcbc860) at /usr/local/include/aegis/impl/core.cpp:1328
#16 0x0000000000566485 in std::__invoke_impl<void, void (aegis::core::*&)(nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer> const&, aegis::shards::shard*), aegis::core*&, nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer> const&, aegis::shards::shard*>(std::__invoke_memfun_deref, void (aegis::core::*&)(nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer> const&, aegis::shards::shard*), aegis::core*&, nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer> const&, aegis::shards::shard*&&) (__f=
    @0xccfe80: (void (aegis::core::*)(aegis::core * const, const nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer> &, aegis::shards::shard *)) 0x44bdc6 <aegis::core::ws_guild_delete(nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer> const&, aegis::shards::shard*)>,
    __t=@0xccfe90: 0x7ffe33bf6370) at /usr/local/include/c++/10.0.0/bits/invoke.h:73
#17 0x0000000000563f3b in std::__invoke<void (aegis::core::*&)(nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer> const&, aegis::shards::shard*), aegis::core*&, nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer> const&, aegis::shards::shard*>(void (aegis::core::*&)(nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer> const&, aegis:---Type <return> to continue, or q <return> to quit---q