Thread 16 "QThread" received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7fffb59cd700 (LWP 1976)] 0x00007ffff7a2b5bf in std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_add_ref_lock_nothrow (this=0x7fffac004640) at /usr/include/c++/6/bits/shared_ptr_base.h:282 282 _Atomic_word __count = _M_get_use_count(); bt #0 0x00007ffff7a2b5bf in std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_add_ref_lock_nothrow (this=0x7fffac004640) at /usr/include/c++/6/bits/shared_ptr_base.h:282 #1 0x00007ffff7a2c561 in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::__shared_count (this=0x7fffb51ce0f8, __r=...) at /usr/include/c++/6/bits/shared_ptr_base.h:843 #2 0x00007ffff6c24bfa in std::__shared_ptr::__shared_ptr (this=0x7fffb51ce0f0, __r=...) at /usr/include/c++/6/bits/shared_ptr_base.h:1150 #3 0x00007ffff6c249a0 in std::shared_ptr::shared_ptr (this=0x7fffb51ce0f0, __r=std::weak_ptr (count 8, weak 5) 0x7fffac004530) at /usr/include/c++/6/bits/shared_ptr.h:328 #4 0x00007ffff6c24544 in std::weak_ptr::lock (this=0x7fffac18d0b8) at /usr/include/c++/6/bits/shared_ptr.h:527 #5 0x00007ffff71a83e6 in octave::symbol_record::symbol_record_rep::get_fwd_scope_context (this=0x7fffac18d090) at ../octave-src/libinterp/corefcn/symrec.cc:52 #6 0x00007ffff7a2b750 in octave::symbol_record::symbol_record_rep::varval (this=0x7fffac18d090, context=0) at ../octave-src/libinterp/corefcn/symrec.h:150 repeated 104339 times #104345 0x00007ffff7a2b774 in octave::symbol_record::symbol_record_rep::varval (this=0x7fffac18d130, context=0) at ../octave-src/libinterp/corefcn/symrec.h:150 #104346 0x00007ffff7a2b900 in octave::symbol_record::varval (this=0x7fffb59c4070, context=0) at ../octave-src/libinterp/corefcn/symrec.h:626 #104347 0x00007ffff6d01a38 in octave::symbol_record::find (this=0x7fffb59c4070, context=0, args=...) at ../octave-src/libinterp/corefcn/symrec.h:584 #104348 0x00007ffff6cf8b08 in octave::tree_evaluator::visit_identifier (this=0x7fffac002b18, expr=...) at ../octave-src/libinterp/parse-tree/pt-eval.cc:1772 #104349 0x00007ffff6cd1f00 in octave::tree_identifier::accept (this=0x7fffac19de60, tw=...) at ../octave-src/libinterp/parse-tree/pt-id.h:134 #104350 0x00007ffff6b83226 in octave::tree_evaluator::evaluate (this=0x7fffac002b18, expr=0x7fffac19de60, nargout=0) at ../octave-src/libinterp/parse-tree/pt-eval.h:312 #104351 0x00007ffff6cfc97f in octave::tree_evaluator::visit_statement (this=0x7fffac002b18, stmt=...) at ../octave-src/libinterp/parse-tree/pt-eval.cc:2775 #104352 0x00007ffff6d1b5c8 in octave::tree_statement::accept (this=0x7fffac417e70, tw=...) at ../octave-src/libinterp/parse-tree/pt-stmt.h:119 #104353 0x00007ffff6cfcc24 in octave::tree_evaluator::visit_statement_list (this=0x7fffac002b18, lst=...) at ../octave-src/libinterp/parse-tree/pt-eval.cc:2844 #104354 0x00007ffff6b83756 in octave::tree_statement_list::accept (this=0x7fffac1f82a0, tw=...) at ../octave-src/libinterp/parse-tree/pt-stmt.h:194 #104355 0x00007ffff6cf7a6c in octave::tree_evaluator::execute_user_script (this=0x7fffac002b18, user_script=..., nargout=0, args=...) at ../octave-src/libinterp/parse-tree/pt-eval.cc:1512 #104356 0x00007ffff6c1ee53 in octave_user_script::call (this=0x7fffac1d9450, tw=..., nargout=0, args=...) at ../octave-src/libinterp/octave-value/ov-usr-fcn.cc:168 #104357 0x00007ffff6cf8c1d in octave::tree_evaluator::visit_identifier (this=0x7fffac002b18, expr=...) at ../octave-src/libinterp/parse-tree/pt-eval.cc:1797 #104358 0x00007ffff6cd1f00 in octave::tree_identifier::accept (this=0x7fffac182d10, tw=...) at ../octave-src/libinterp/parse-tree/pt-id.h:134 #104359 0x00007ffff6b83226 in octave::tree_evaluator::evaluate (this=0x7fffac002b18, expr=0x7fffac182d10, nargout=0) at ../octave-src/libinterp/parse-tree/pt-eval.h:312 #104360 0x00007ffff6cfc97f in octave::tree_evaluator::visit_statement (this=0x7fffac002b18, stmt=...) at ../octave-src/libinterp/parse-tree/pt-eval.cc:2775 #104361 0x00007ffff6d1b5c8 in octave::tree_statement::accept (this=0x7fffac4281b0, tw=...) at ../octave-src/libinterp/parse-tree/pt-stmt.h:119 #104362 0x00007ffff6cfcc24 in octave::tree_evaluator::visit_statement_list (this=0x7fffac002b18, lst=...) at ../octave-src/libinterp/parse-tree/pt-eval.cc:2844 #104363 0x00007ffff6b83756 in octave::tree_statement_list::accept (this=0x7fffac1f82a0, tw=...) at ../octave-src/libinterp/parse-tree/pt-stmt.h:194 #104364 0x00007ffff6cf7a6c in octave::tree_evaluator::execute_user_script (this=0x7fffac002b18, user_script=..., nargout=0, args=...) at ../octave-src/libinterp/parse-tree/pt-eval.cc:1512 #104365 0x00007ffff6c1ee53 in octave_user_script::call (this=0x7fffac1d9450, tw=..., nargout=0, args=...) at ../octave-src/libinterp/octave-value/ov-usr-fcn.cc:168 #104366 0x00007ffff6cf8c1d in octave::tree_evaluator::visit_identifier (this=0x7fffac002b18, expr=...) at ../octave-src/libinterp/parse-tree/pt-eval.cc:1797 #104367 0x00007ffff6cd1f00 in octave::tree_identifier::accept (this=0x7fffac420cc0, tw=...) at ../octave-src/libinterp/parse-tree/pt-id.h:134 #104368 0x00007ffff6b83226 in octave::tree_evaluator::evaluate (this=0x7fffac002b18, expr=0x7fffac420cc0, nargout=0) at ../octave-src/libinterp/parse-tree/pt-eval.h:312 #104369 0x00007ffff6cfc97f in octave::tree_evaluator::visit_statement (this=0x7fffac002b18, stmt=...) at ../octave-src/libinterp/parse-tree/pt-eval.cc:2775 #104370 0x00007ffff6d1b5c8 in octave::tree_statement::accept (this=0x7fffac4365b0, tw=...) at ../octave-src/libinterp/parse-tree/pt-stmt.h:119 ---Type to continue, or q to quit--- #104371 0x00007ffff6cfcc24 in octave::tree_evaluator::visit_statement_list (this=0x7fffac002b18, lst=...) at ../octave-src/libinterp/parse-tree/pt-eval.cc:2844 #104372 0x00007ffff6b83756 in octave::tree_statement_list::accept (this=0x7fffac196520, tw=...) at ../octave-src/libinterp/parse-tree/pt-stmt.h:194 #104373 0x00007ffff6cf2504 in octave::tree_evaluator::repl (this=0x7fffac002b18, interactive=true) at ../octave-src/libinterp/parse-tree/pt-eval.cc:105 #104374 0x00007ffff704e4d9 in octave::interpreter::main_loop (this=0x7fffac001ed0) at ../octave-src/libinterp/corefcn/interpreter.cc:949 #104375 0x00007ffff704d45d in octave::interpreter::execute (this=0x7fffac001ed0) at ../octave-src/libinterp/corefcn/interpreter.cc:694 #104376 0x00007ffff79a0b2b in octave::octave_interpreter::execute (this=0x5555557fb1d0) at ../octave-src/libgui/src/main-window.cc:146 #104377 0x00007ffff7a513b0 in octave::octave_interpreter::qt_static_metacall (_o=0x5555557fb1d0, _c=QMetaObject::InvokeMetaMethod, _id=2, _a=0x55555594df20) at libgui/src/moc-main-window.cc:87 #104378 0x00007ffff2ef6499 in QObject::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #104379 0x00007ffff37acb8c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 #104380 0x00007ffff37b4341 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 #104381 0x00007ffff79b1144 in octave::octave_qapplication::notify (this=0x5555557fb820, receiver=0x5555557fb1d0, ev=0x555555b203a0) at ../octave-src/libgui/src/main-window.cc:2783 #104382 0x00007ffff2ec99e0 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #104383 0x00007ffff2ecc16d in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #104384 0x00007ffff2f1dc43 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #104385 0x00007fffeb07c7f7 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #104386 0x00007fffeb07ca60 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #104387 0x00007fffeb07cb0c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #104388 0x00007ffff2f1e04f in QEventDispatcherGlib::processEvents(QFlags) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #104389 0x00007ffff2ec79ca in QEventLoop::exec(QFlags) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #104390 0x00007ffff2cf50f3 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #104391 0x00007ffff2cf9da8 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #104392 0x00007ffff416e494 in start_thread (arg=0x7fffb59cd700) at pthread_create.c:333 #104393 0x00007ffff3eb0acf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97