Re: [Sbcl-devel] breakpointed trace

[Ingvar <in...@ca...>]

> Hi,
> 
> Here's an interesting one.  In an x86/SBCL wot I built myself,
>   (trace sb-c::logxor-derive-type-aux :encapsulate nil)
>   (defun foo (x y) (logxor x y))
> works as expected.
> 
> In an x86/SBCL wot I downloaded from Debian,
>   (trace sb-c::logxor-derive-type-aux :encapsulate nil)
>   (defun foo (x y) (logxor x y))
> gives me a segmentation fault, followed by 10 errors of the "NIL is
> not of type SB-DI::FRAME" variety.
> 
> This smells of libc (or equivalent) skew, but I can't see why.  I seem
> to remember that we had similar problems with **environ, but the
> details are getting a bit hazy at my advanced age.  Does anyone else
> have any ideas?

In an x86/SBCL, on Debian, self-built, I see the following:

This is SBCL 0.8.7.57, an implementation of ANSI Common Lisp.

More information about SBCL is available at <http://www.sbcl.org/>.
SBCL is free software, provided as is, with absolutely no warranty.
It is mostly in the public domain; some portions are provided under
BSD-style licenses.  See the CREDITS and COPYING files in the
distribution for more information.
* (trace sb-c::logxor-derive-type-aux :encapsulate nil)

(SB-C::LOGXOR-DERIVE-TYPE-AUX)
* (defun foo (x y) (logxor x y))
  0: (SB-C::LOGXOR-DERIVE-TYPE-AUX
      3
      #<SB-KERNEL:NUMERIC-TYPE INTEGER>
      #<SB-KERNEL:NUMERIC-TYPE INTEGER>
      #<unavailable argument>)[:EXTERNAL]
  0: SB-C::LOGXOR-DERIVE-TYPE-AUX returned #<SB-KERNEL:NUMERIC-TYPE INTEGER>
FOO
* 'works

WORKS

Unfortunately, I don't think I have a Debian-installed SBCL at hand.

//Ingvar