D struct with String type accessing from Python

[alchemypy]

Hi Everyone, I am new to Dlang and i am trying to consume .so 
(Dlang based dynamic library) from Python.

My D program has something like below,


	struct gph
	{
		string x;
	}

	struct myStruct
	{
		pragma(mangle, "Print_gph")
		void Print_gph(gph g)
		{
			stderr.writeln("here: gph ");
			stderr.writeln(g.x);
		
		}
	}

i have created a .so for the same and my Python code looks as 
follows:

	from ctypes import *

	class gph(Structure):
		_fields_ = (
			('x_p', c_char_p),
			('x_len', c_size_t)
		)
		def __init__(self, x):
			self.x_p = x
			self.x_len = len(x)


	so_path = "./test.so"
	lib = CDLL(so_path)

	sample_struct = gph(b'gph')
	lib.SubOcc_gph(c_void_p(),sample_struct)


When i executed i got bellow error,


	here: gph
	src/rt/dwarfeh.d:330: uncaught exception reached top of stack
	This might happen if you're missing a top level catch in your 
fiber or signal handler
	std.exception.ErrnoException@/usr/include/dmd/phobos/std/stdio.d(3170): Enforcement failed (Bad address)
	Aborted


Can you please help me what went wrong here ?