Re: how does one debug a SEGV in scm_threads_prehistory?

[Bruce Korb]

On Wed, Jun 18, 2008 at 12:29 PM, Greg Troxel <address@hidden> wrote:
>  Our main development server was "upgraded" to 64 bits, but mostly
>  still runs 32 bit software,
>  so this is from a 32 bit build on a 64 bit platform.  Naturally, this
>  all works on 32 on 32 and
>  on 64 on 64.  But with 32 on 64, not so well:
>
> I presume you are talking about Linux and going from i386 to
> amd64/x86_64 (not sure which name is used in Linux).  I would be

It depends on which Linux:  SuSE is x86_64 and Debian amd64.
Unclear why the first name needed to be rethought.  Whatever.

> suspicious that the i386 binary is getting linked with some amd64 libs

ldd showed which libguile, and it was the 32 bit flavor.  (I did go there, too.
It's just hard to recount all the rabbit trails I've gone down....)

> somehow - to first order it would seem to be an OS bug if the emulated
> i386 binary doesn't run the same as on i386.  But I could certainly see
> an allowable difference leading to triggering a latent bug in guile.
>
> Can you trigger this with a simple example?  I have i386 and now amd64
> boxes, and would be curious to try the NetBSD i386 binary on amd64, as
> well as native.

"simple example" is always a stumbling block.  Especially when it is happening
in libguile (which is not simple) and triggered by my app (which is as large
as Guile is).  I'll see what I can do.  Probably next week or so.

Thanks - Bruce