Now I compiled the latest version from git with symbols and did a
backtrace under gdb:

Program received signal SIGSEGV, Segmentation fault.
0xaa5c5a00 in ?? ()
(gdb) backtrace
#0 0xaa5c5a00 in ?? ()
#1 0xfffffffb in ?? ()
#2 0xae3d99c0 in ?? ()
#3 0xaa5c59eb in ?? ()
#4 0xabc51f1c in ?? ()
#5 0xb50b298b in ?? () from
/usr/lib/i386-linux-gnu/libjavascriptcoregtk-1.0.so.0
#6 0xb50b298b in ?? () from
/usr/lib/i386-linux-gnu/libjavascriptcoregtk-1.0.so.0
#7 0xb50b2aaf in ?? () from
/usr/lib/i386-linux-gnu/libjavascriptcoregtk-1.0.so.0
#8 0xb50b298b in ?? () from
/usr/lib/i386-linux-gnu/libjavascriptcoregtk-1.0.so.0
#9 0xb50b298b in ?? () from
/usr/lib/i386-linux-gnu/libjavascriptcoregtk-1.0.so.0
#10 0xb50b298b in ?? () from
/usr/lib/i386-linux-gnu/libjavascriptcoregtk-1.0.so.0
#11 0xb50af3e9 in ?? () from
/usr/lib/i386-linux-gnu/libjavascriptcoregtk-1.0.so.0
#12 0xb504b806 in JSC::JITCode::execute(JSC::VM*, JSC::ProtoCallFrame*,
JSC::Register*) () from
/usr/lib/i386-linux-gnu/libjavascriptcoregtk-1.0.so.0
#13 0xb502993f in JSC::Interpreter::executeCall(JSC::ExecState*,
JSC::JSObject*, JSC::CallType, JSC::CallData const&, JSC::JSValue,
JSC::ArgList const&) () from
/usr/lib/i386-linux-gnu/libjavascriptcoregtk-1.0.so.0
#14 0xb516d234 in JSC::call(JSC::ExecState*, JSC::JSValue,
JSC::CallType, JSC::CallData const&, JSC::JSValue, JSC::ArgList const&)
() from /usr/lib/i386-linux-gnu/libjavascriptcoregtk-1.0.so.0
#15 0xb62d2a86 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#16 0xb64a9b3d in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#17 0xb64a9ffe in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#18 0xb64bb96d in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#19 0xb64a38d4 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#20 0xb64a5bd2 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#21 0xb64bf145 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#22 0xb646ede5 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#23 0xb66a2e8c in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#24 0xb66cf3d4 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#25 0xb66a9540 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#26 0xb66a9591 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#27 0xb66abfd5 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#28 0xb66a9abf in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#29 0xb66acc22 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#30 0xb66accd1 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#31 0xb67facbf in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#32 0xb67faa76 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#33 0xb6807838 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#34 0xb6865976 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#35 0xb685b005 in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#36 0xb70d972d in ?? () from
/usr/lib/i386-linux-gnu/libwebkitgtk-1.0.so.0
#37 0xb549a9f5 in ?? () from /usr/lib/i386-linux-gnu/libgio-2.0.so.0
#38 0xb54c12e7 in ?? () from /usr/lib/i386-linux-gnu/libgio-2.0.so.0
#39 0xb54c131b in ?? () from /usr/lib/i386-linux-gnu/libgio-2.0.so.0
#40 0xb4c38510 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#41 0xb4c3bcc3 in g_main_context_dispatch () from
/lib/i386-linux-gnu/libglib-2.0.so.0
#42 0xb4c3c0d9 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#43 0xb4c3c489 in g_main_loop_run () from
/lib/i386-linux-gnu/libglib-2.0.so.0
#44 0xb5b9b1b5 in gtk_main () from
/usr/lib/i386-linux-gnu/libgtk-x11-2.0.so.0
#45 0x0804f5aa in main ()