DerelictGL3 glGenBuffers segmentation fault.

[Kevin]

I'm working a library with DerelictGL3.
using branch 2.0

import derelict.opengl;
import std.stdio : writeln;

struct VertexBuffer
{
     GLuint vbo;
     GLsizei count;

     this(GLsizei n)
     {
         writeln("creating vbo");
         glGenBuffers(n, &vbo);
         writeln("created vbo");
         count = n;
         writeln("exiting vbo");
     }

     // more code
}

When I import my library into my program.
glGenBuffers segmentation fault.

When I copy VertexBuffer into main code. It works fine.
Why am I getting segmentation fault from library ?