Game crashes when attempting to save a game file

SIGSEGV

FATAL: terminate has been called

current stack

Traceback (most recent call last):
  File ?, in _start+0x29 [0x401e19]
  File ?, in __libc_start_main+0xf0 [0x7f9109eb4700]
  File ?, in main+0x10b [0x403a84]
  File ?, in ? [0x403933]
  File ?, in PyInit_run+0x938 [0x403404]
  File ?, in ? [0x7f910d2695f8]
  File ?, in PyEval_EvalCodeEx+0x8c6 [0x7f910d2f8de6]
  File ?, in PyEval_EvalFrameEx+0x85a2 [0x7f910d2f8162]
  File ?, in PyEval_EvalFrameEx+0x835f [0x7f910d2f7f1f]
  File ?, in ? [0x7f90fd45bbe4]
  File ?, in ? [0x7f90fd45b839]
  File ?, in openage::run_game(openage::main_arguments const&)+0x745 [0x7f910ce9f796]
  File ?, in openage::Engine::run()+0x1f [0x7f910ce7909d]
  File ?, in openage::Engine::loop()+0x18e [0x7f910ce78ae2]
  File ?, in openage::input::InputManager::on_input(SDL_Event*)+0x98 [0x7f910cecf1c6]
  File ?, in openage::input::InputManager::set_state(openage::input::Event const&, bool)+0x5e [0x7f910cecf124]
  File ?, in openage::input::InputManager::trigger(openage::input::Event const&)+0xde [0x7f910cecef30]
  File ?, in openage::input::InputContext::execute_if_bound(openage::input::action_arg_t const&)+0x3f [0x7f910cecd9f9]
  File ?, in std::function<void (openage::input::action_arg_t const&)>::operator()(openage::input::action_arg_t const&) const+0x13 [0x7f910cecdeeb]
  File ?, in ? [0x7f910ce82b2b]
  File ?, in ? [0x7f910ce824a4]
  File ?, in openage::options::OptionNode::do_action(std::string const&)+0x21 [0x7f910cea08a9]
  File ?, in openage::options::OptionAction::do_action()+0xd [0x7f910cea0087]
  File ?, in std::function<openage::options::OptionValue ()>::operator()() const+0x13 [0x7f910cea1d2b]
  File ?, in ? [0x7f910ce9a224]
  File ?, in openage::gameio::save(openage::GameMain*, std::string)+0x780 [0x7f910ce88d61]
  File ?, in openage::gameio::save_unit(std::basic_ofstream<char, std::char_traits<char> >&, openage::Unit*)+0x100 [0x7f910ce88391]
  File ?, in ? [0x7f9109ec8a50]
  File ?, in ? [0x7f910cecbd39]
  File ?, in ? [0x7f910a8009e1]
  File ?, in ? [0x7f910a800996]
  File ?, in openage::error::terminate_handler()+0xe2 [0x7f910cecbbbf]
  File ?, in openage::error::StackAnalyzer::analyze()+0x77 [0x7f910cecc27d]

standard terminate handler

terminate called without an active exception
Aborted (core dumped)

Start with the stack-trace entry points openage::gameio::save and openage::gameio::save_unit, then follow the save action from openage::options::OptionAction::do_action. Reproduce the save operation and identify the cause of the SIGSEGV. Done means saving a game file completes without the reported crash.