(gdb) bt full
#0  0x0000000000b227af in CowData<String>::get (p_index=1, this=0x7fff08c82de0) at ./core/cowdata.h:156
        __FUNCTION__ = <optimized out>
#1  Vector<String>::operator[] (p_index=1, this=0x7fff08c82dd8) at ./core/vector.h:87
No locals.
#2  ExtendGDScriptParser::parse_documentation (this=0x7fff08c82cc0, p_line=0, p_docs_down=true) at modules/gdscript/language_server/gdscript_extend_parser.cpp:412
        next_line = {_cowdata = {_ptr = 0x7fff08c82de8 L"\x99a5e30翿\x999f310翿"}}
        line_comment = {_cowdata = {_ptr = 0x7fff088360e0 L"Null"}}
        i = 0
        __FUNCTION__ = "parse_documentation"
        doc_lines = {_data = 0x0}
        step = 1
        start_line = 0
        doc = {_cowdata = {_ptr = 0x7fff088360e0 L"Null"}}
#3  0x0000000000b1ba21 in ExtendGDScriptParser::parse_class_symbol (this=0x7fff08c82cc0, p_class=0x7fff099c3af0, r_symbol=...) at modules/gdscript/language_server/gdscript_extend_parser.cpp:159
        uri = {_cowdata = {_ptr = 0x7fff0999f0f0 L"file:///tmp/lsp_bug/Node2D.gd"}}
        is_root_class = true
        __FUNCTION__ = "parse_class_symbol"
#4  0x0000000000b1aa81 in ExtendGDScriptParser::update_symbols (this=0x7fff08c82cc0) at modules/gdscript/language_server/gdscript_extend_parser.cpp:87
        gdclass = 0x7fff099c3af0
        head = 0x7fff099c3af0
#5  0x0000000000b2d152 in ExtendGDScriptParser::parse (this=0x7fff08c82cc0, p_code=..., p_path=...) at modules/gdscript/language_server/gdscript_extend_parser.cpp:788
        err = ERR_PARSE_ERROR
#6  0x000000000071a326 in GDScriptWorkspace::parse_script (this=0xc72a410, p_path=..., p_content=...) at modules/gdscript/language_server/gdscript_workspace.cpp:420
        parser = 0x7fff08c82cc0
        err = 32767
        last_parser = 0x8fd4dc0
        last_script = 0x7fff215f93e0
#7  0x0000000000706089 in GDScriptTextDocument::sync_script_content (this=0xc72a660, p_path=..., p_content=...) at modules/gdscript/language_server/gdscript_text_document.cpp:425
        path = {_cowdata = {_ptr = 0x7fff0886db80 L"res://Node2D.gd"}}
        error = OK
        script = {reference = 0x7fff215f9410}
#8  0x00000000006fbd3c in GDScriptTextDocument::didSave (this=0xc72a660, p_param=...) at modules/gdscript/language_server/gdscript_text_document.cpp:88
        doc = {uri = {_cowdata = {_ptr = 0x7fff09971510 L"file:///tmp/lsp_bug/Node2D.gd"}}, languageId = {_cowdata = {_ptr = 0x7fff08407810 L"Null"}}, version = 0, text = {_cowdata = {_ptr = 0x7fff08c82f10 L"Null"}}}
        dict = {_p = 0x7fff08c87530}
        text = {_cowdata = {_ptr = 0x7fff088360e0 L"Null"}}
#9  0x00000000006f5d1b in MethodBind1<Variant const&>::call (this=0xc727a90, p_object=0xc72a660, p_args=0x7fff215f9750, p_arg_count=1, r_error=...) at ./core/method_bind.gen.inc:775
        __FUNCTION__ = "call"
        instance = 0xc72a660
#10 0x000000000474cefe in Object::call (this=0xc72a660, p_method=..., p_args=0x7fff215f9750, p_argcount=1, r_error=...) at core/object.cpp:918
        __FUNCTION__ = "call"
        ret = {type = Variant::NIL, _data = {_bool = 200, _int = 140733354466248, _real = 6.9531515665771897e-310, _transform2d = 0x7fff0999dbc8, _aabb = 0x7fff0999dbc8, _basis = 0x7fff0999dbc8, _transform = 0x7fff0999dbc8, _ptr = 0x7fff0999dbc8, _mem = "\310ۙ\t\377\177\000\000\320ۙ\t\377\177\000"}}
        _debug_lock = {obj = 0xc72a660}
        method = 0xc727a90
#11 0x000000000474c724 in Object::callv (this=0xc72a660, p_method=..., p_args=...) at core/object.cpp:827
        argptrs = 0x7fff215f9750
        ce = {error = Variant::CallError::CALL_OK, argument = 208828992, expected = Variant::NIL}
        ret = {type = 208828992, _data = {_bool = 64, _int = 208828992, _real = 1.0317523080285651e-315, _transform2d = 0xc727a40, _aabb = 0xc727a40, _basis = 0xc727a40, _transform = 0xc727a40, _ptr = 0xc727a40, _mem = "@zr\f\000\000\000\000\000\230_!\377\177\000"}}
        __FUNCTION__ = "callv"
#12 0x0000000000745dfe in JSONRPC::process_action (this=0x8fd4c78, p_action=..., p_process_arr_elements=true) at modules/jsonrpc/jsonrpc.cpp:129
        call_ret = {type = Variant::NIL, _data = {_bool = false, _int = 0, _real = 0, _transform2d = 0x0, _aabb = 0x0, _basis = 0x0, _transform = 0x0, _ptr = 0x0, _mem = '\000' <repeats 15 times>}}
        dict = {_p = 0x7fff08891aa0}
        method = {_cowdata = {_ptr = 0x7fff084057e0 L"didSave"}}
        args = {_p = 0x7fff0999dbc0}
        object = 0xc72a660
        id = {type = Variant::NIL, _data = {_bool = false, _int = 0, _real = 0, _transform2d = 0x0, _aabb = 0x0, _basis = 0x0, _transform = 0x0, _ptr = 0x0, _mem = "\000\000\000\000\000\000\000\000 \233_!\377\177\000"}}
        ret = {type = Variant::NIL, _data = {_bool = 156, _int = 140733331830172, _real = 6.9531504482064389e-310, _transform2d = 0x7fff0840759c, _aabb = 0x7fff0840759c, _basis = 0x7fff0840759c, _transform = 0x7fff0840759c, _ptr = 0x7fff0840759c, _mem = "\234u@\b\377\177\000\000К_!\377\177\000"}}
#13 0x0000000000746803 in JSONRPC::process_string (this=0x8fd4c78, p_input=...) at modules/jsonrpc/jsonrpc.cpp:165
        ret = {type = Variant::NIL, _data = {_bool = false, _int = 0, _real = 0, _transform2d = 0x0, _aabb = 0x0, _basis = 0x0, _transform = 0x0, _ptr = 0x0, _mem = "\000\000\000\000\000\000\000\000\020\233_!\377\177\000"}}
        input = {type = Variant::DICTIONARY, _data = {_bool = 160, _int = 140733336591008, _real = 6.9531506834229902e-310, _transform2d = 0x7fff08891aa0, _aabb = 0x7fff08891aa0, _basis = 0x7fff08891aa0, _transform = 0x7fff08891aa0, _ptr = 0x7fff08891aa0, _mem = "\240\032\211\b\377\177\000\000\020\233_!\377\177\000"}}
        err_message = {_cowdata = {_ptr = 0x0}}
        err_line = 0
#14 0x00000000006e3d46 in GDScriptLanguageProtocol::process_message (this=0x8fd4c78, p_text=...) at modules/gdscript/language_server/gdscript_language_protocol.cpp:143
        ret = {_cowdata = {_ptr = 0x7fff099c7b1c L""}}
#15 0x00000000006e33b0 in GDScriptLanguageProtocol::LSPeer::handle_data (this=0x7fff08001240) at modules/gdscript/language_server/gdscript_language_protocol.cpp:96
        msg = {_cowdata = {_ptr = 0x7fff084075a0 L"{\"method\": \"textDocument/didSave\", \"jsonrpc\": \"2.0\", \"params\": {\"textDocument\": {\"uri\": \"file:///tmp/lsp_bug/Node2D.gd\"}}}"}}
        output = {_cowdata = {_ptr = 0x7fff0999f050 L" is out of bounds ("}}
        read = 1
        __FUNCTION__ = "handle_data"
#16 0x00000000006e79f0 in GDScriptLanguageProtocol::poll (this=0x8fd4c78) at modules/gdscript/language_server/gdscript_language_protocol.cpp:244
        err = 26425268
        err = OK
        peer = {reference = 0x7fff08001240}
        status = StreamPeerTCP::STATUS_CONNECTED
        id = 0x7fff084013a0
#17 0x00000000006f87be in GDScriptLanguageServer::thread_main (p_userdata=0x8fd4a50) at modules/gdscript/language_server/gdscript_language_server.cpp:81
        self = 0x8fd4a50
#18 0x000000000491855f in Thread::callback (p_self=0x8fd4dd0, p_settings=..., p_callback=0x6f8796 <GDScriptLanguageServer::thread_main(void*)>, p_userdata=0x8fd4a50) at core/os/thread.cpp:79
No locals.
#19 0x00000000049194a7 in std::__invoke_impl<void, void (*)(Thread*, Thread::Settings const&, void (*)(void*), void*), Thread*, Thread::Settings, void (*)(void*), void*> (__f=@0xd04e818: 0x49184c2 <Thread::callback(Thread*, Thread::Settings const&, void (*)(void*), void*)>) at /usr/include/c++/11.1.0/bits/invoke.h:61
No locals.
#20 0x000000000491932a in std::__invoke<void (*)(Thread*, Thread::Settings const&, void (*)(void*), void*), Thread*, Thread::Settings, void (*)(void*), void*> (__fn=@0xd04e818: 0x49184c2 <Thread::callback(Thread*, Thread::Settings const&, void (*)(void*), void*)>) at /usr/include/c++/11.1.0/bits/invoke.h:96
No locals.
#21 0x00000000049191e5 in std::thread::_Invoker<std::tuple<void (*)(Thread*, Thread::Settings const&, void (*)(void*), void*), Thread*, Thread::Settings, void (*)(void*), void*> >::_M_invoke<0ul, 1ul, 2ul, 3ul, 4ul> (this=0xd04e7f8) at /usr/include/c++/11.1.0/bits/std_thread.h:253
No locals.
#22 0x000000000491914a in std::thread::_Invoker<std::tuple<void (*)(Thread*, Thread::Settings const&, void (*)(void*), void*), Thread*, Thread::Settings, void (*)(void*), void*> >::operator() (this=0xd04e7f8) at /usr/include/c++/11.1.0/bits/std_thread.h:260
No locals.
#23 0x000000000491912e in std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (*)(Thread*, Thread::Settings const&, void (*)(void*), void*), Thread*, Thread::Settings, void (*)(void*), void*> > >::_M_run (this=0xd04e7f0) at /usr/include/c++/11.1.0/bits/std_thread.h:211
No locals.
#24 0x0000000004e33c24 in execute_native_thread_routine ()
No symbol table info available.
#25 0x00007ffff7d68259 in start_thread () from /usr/lib/libpthread.so.0
No symbol table info available.
#26 0x00007ffff7b465e3 in clone () from /usr/lib/libc.so.6
No symbol table info available.
(gdb)