thanks alot, the "bt" command has been proven most usefull
here is the output of a crash (dragging a scout to newfleet)
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1223661872 (LWP 17958)]
0x0000000d in ?? ()
(gdb) bt
#0 0x0000000d in ?? ()
#1 0x4ee197a4 in __dynamic_cast () from /usr/lib/gcc/i686-pc-linux-gnu/4.1.0/libstdc++.so.6
#2 0xb7d11154 in GG::Wnd::AttachChild () from /usr/local/lib/libGiGi.so
#3 0x082f186f in (anonymous namespace)::ShipDataPanel::SetShipIcon ()
#4 0x082f1bd4 in (anonymous namespace)::ShipDataPanel::Refresh ()
#5 0x08093eec in boost::function0<void, std::allocator<void> >::operator() ()
#6 0x08094091 in boost::operator++<boost::signals::detail::slot_call_iterator<boost::signals::detail::call_bound0<void>::caller<boost::function<void ()(), std::allocator<void> > >, boost::signals::detail::named_slot_map_iterator>, boost::signals::detail::unusable, boost::single_pass_traversal_tag, boost::signals::detail::unusable const&, int> ()
#7 0x080944d5 in boost::signal0<void, boost::last_value<void>, int, std::less<int>, boost::function<void ()(), std::allocator<void> > >::operator() ()
#8 0x0811eb43 in Fleet::AddShip ()
#9 0x081d8e28 in NewFleetOrder::ExecuteImpl ()
#10 0x081d58f2 in Order::Execute ()
#11 0x081e66d7 in OrderSet::IssueOrder ()
#12 0x082e2181 in FleetWnd::CreateNewFleetFromDrops ()
#13 0x082f08ba in boost::function2<void, Ship*, std::vector<int, std::allocator<int> > const&, std::allocator<void> >::operator() ()
#14 0x082f0a71 in boost::operator++<boost::signals::detail::slot_call_iterator<boost::signals::detail::call_bound2<void>::caller<Ship*, std::vector<int, std::allocator<int> > const&, boost::function<void ()(Ship*, std::vector<int, std::allocator<int> > const&), std::allocator<void> > >, boost::signals::detail::named_slot_map_iterator>, boost::signals::detail::unusable, boost::single_pass_traversal_tag, boost::signals::detail::unusable const&, int> ()
#15 0x082f0ec5 in boost::signal2<void, Ship*, std::vector<int, std::allocator<int> > const&, boost::last_value<void>, int, std::less<int>, boost::function<void ()(Ship*, std::vector<int, std::allocator<int> > const&), std::allocator<void> > >::operator() ()
#16 0x082dd13e in FleetDataPanel::AcceptDrops ()
#17 0xb7cb19ed in GG::GUI::HandleGGEvent () from /usr/local/lib/libGiGi.so
#18 0xb7ee3e35 in SDLGUI::HandleSystemEvents () from /usr/local/lib/libGiGiSDL.so
#19 0xb7c961c8 in GG::EventPump::operator() () from /usr/local/lib/libGiGi.so
#20 0xb7ee4254 in SDLGUI::Run () from /usr/local/lib/libGiGiSDL.so
#21 0xb7cacb61 in GG::GUI::operator() () from /usr/local/lib/libGiGi.so
#22 0xb7ee401d in SDLGUI::operator() () from /usr/local/lib/libGiGiSDL.so
#23 0x082754a5 in main ()
(gdb)