Program received signal SIGSEGV, Segmentation fault.
0x000000000055d84f in Yosys::RTLIL::IdString::c_str() const ()
(gdb) bt
#0  0x000000000055d84f in Yosys::RTLIL::IdString::c_str() const ()
#1  0x00000000009280be in (anonymous namespace)::signal_to_mux_tree(Yosys::RTLIL::Module*, (anonymous namespace)::SnippetSwCache&, Yosys::hashlib::dict<Yosys::RTLIL::SwitchRule*, bool, Yosys::hashlib::hash_ptr_ops>&, Yosys::RTLIL::CaseRule*, Yosys::RTLIL::SigSpec const&, Yosys::RTLIL::SigSpec const&, bool) ()
#2  0x00000000009263a7 in (anonymous namespace)::ProcMuxPass::execute(std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, Yosys::RTLIL::Design*) ()
#3  0x0000000000522459 in Yosys::Pass::call(Yosys::RTLIL::Design*, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >) ()
#4  0x00000000005221c5 in Yosys::Pass::call(Yosys::RTLIL::Design*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >) ()
#5  0x000000000091fd77 in (anonymous namespace)::ProcPass::execute(std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, Yosys::RTLIL::Design*) ()
#6  0x0000000000522459 in Yosys::Pass::call(Yosys::RTLIL::Design*, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >) ()
#7  0x0000000000522063 in Yosys::Pass::call(Yosys::RTLIL::Design*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >) ()
#8  0x000000000052289b in Yosys::Pass::call_on_module(Yosys::RTLIL::Design*, Yosys::RTLIL::Module*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >) ()
#9  0x00000000007a7140 in (anonymous namespace)::TechmapWorker::techmap_module(Yosys::RTLIL::Design*, Yosys::RTLIL::Module*, Yosys::RTLIL::Design*, std::set<Yosys::RTLIL::Cell*, std::less<Yosys::RTLIL::Cell*>, std::allocator<Yosys::RTLIL::Cell*> >&, std::map<Yosys::RTLIL::IdString, std::set<Yosys::RTLIL::IdString, Yosys::RTLIL::sort_by_id_str, std::allocator<Yosys::RTLIL::IdString> >, std::less<Yosys::RTLIL::IdString>, std::allocator<std::pair<Yosys::RTLIL::IdString const, std::set<Yosys::RTLIL::IdString, Yosys::RTLIL::sort_by_id_str, std::allocator<Yosys::RTLIL::IdString> > > > > const&, bool) ()
#10 0x00000000007a4629 in (anonymous namespace)::TechmapPass::execute(std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, Yosys::RTLIL::Design*) ()
#11 0x0000000000522459 in Yosys::Pass::call(Yosys::RTLIL::Design*, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >) ()
#12 0x00000000005221c5 in Yosys::Pass::call(Yosys::RTLIL::Design*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >) ()
#13 0x0000000000522cc8 in Yosys::ScriptPass::run(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >) ()
#14 0x00000000009d7906 in (anonymous namespace)::SynthIce40Pass::script() ()
#15 0x00000000009d660e in (anonymous namespace)::SynthIce40Pass::execute(std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, Yosys::RTLIL::Design*) ()
#16 0x0000000000522459 in Yosys::Pass::call(Yosys::RTLIL::Design*, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >) ()
#17 0x00000000005221c5 in Yosys::Pass::call(Yosys::RTLIL::Design*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >) ()
#18 0x000000000057a30e in Yosys::run_frontend(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, Yosys::RTLIL::Design*) ()
#19 0x0000000000512965 in main ()