00 ntdll!NtWaitForSingleObject
01 KERNELBASE!WaitForSingleObjectEx
02 unicorn!qemu_thread_join
03 unicorn!pause_all_vcpus_x86_64
04 unicorn!uc_emu_start
05 _ctypes!ffi_call_AMD64
06 _ctypes!ffi_call
07 _ctypes!_call_function_pointer
08 _ctypes!_ctypes_callproc
09 _ctypes!PyCFuncPtr_call
0a python27!PyObject_Call
0b python27!do_call
0c python27!call_function
0d python27!PyEval_EvalFrameEx
0e python27!PyEval_EvalCodeEx
0f python27!fast_function
10 python27!call_function
11 python27!PyEval_EvalFrameEx
12 python27!PyEval_EvalCodeEx
13 python27!PyEval_EvalCode
14 python27!run_mod
15 python27!PyRun_FileExFlags
16 python27!PyRun_File
17 pykd!py
18 dbgeng!ExtensionInfo::CallA
19 dbgeng!ExtensionInfo::Call
1a dbgeng!ExtensionInfo::CallAny
1b dbgeng!ParseBangCmd
1c dbgeng!ProcessCommands
1d dbgeng!ProcessCommandsAndCatch
1e dbgeng!Execute
1f dbgeng!DebugClient::ExecuteWide
20 windbg!ProcessCommand
21 windbg!ProcessEngineCommands
22 windbg!EngineLoop
23 KERNEL32!BaseThreadInitThunk
24 ntdll!RtlUserThreadStart



00 msvcrt!_except_validate_jump_buffer   <---  crash
01 msvcrt!longjmp
02 unicorn!cpu_loop_exit_x86_64
03 unicorn!helper_rdmsr
04 unicorn!helper_hlt
05 unicorn!have_bmi1_x86_64
06 0x0

It maybe not pykd bug. Why unicorn.dll uses standard msvcrt.dll ? Python on Windows always has a problem with msvcrt.dll. If you build unicorn.dll with Visual Studio, try to use msvcrt from vcredst.