[cffi-devel] How do I debug a memory fault?

[James Bielman]

On Sun, 2007-10-07 at 13:16 -0400, Liam Healy wrote:
> I am using CFFI in SBCL on Debian GNU/Linux etch (amd64).  I have had
> a great deal of success interfacing to the GNU scientific library
> (GSL).  Usually, when I get a "memory fault" I quickly can see my
> mistake in defining the interface, and once fixed, the error goes
> away.
> 
> I can't figure this one out however.  The interface is:
>   gsl_odeiv_step * gsl_odeiv_step_alloc (const gsl_odeiv_step_type *
> T, size_t dim)
> I attempt to call this with a predefined pointer,
>   (describe *step-rk8pd*)
>   #.(SB-SYS:INT-SAP #X2B31DAEB0328) is a SB-SYS:SYSTEM-AREA-POINTER.
> and I get a memory fault.  What is the best way to debug this?

Hi Liam,

You don't show how you are defining *STEP-RK8PD* here, but I am
wondering if what you actually have is the address of that variable.

Are you defining this with DEFCVAR?

James