From: Lars Rune Nøstdal
Subject: `call-next-method' gives warings
Date: Sun, 28 May 2006 04:06:01 +0000
Message-ID: <1148789160.938210.320760@i39g2000cwa.googlegroups.com>

Hi again,
I'm messing with `call-next-method', but keep getting warnings like
"asserted type conflicts with derived type" even for very simple cases.
This is SBCL-0.9.13.

  (defclass A ()
    ())

  (defclass B (A)
    ())

  (defmethod test ((b B))
    (call-next-method)
    (write-line "B"))

When compiling `test' i get:

  ; caught warning:
  ;   Asserted type (mod 536870911) conflicts with derived type
  ;   (values (or function sb-pcl::method-call
sb-pcl::fast-method-call) &optional).
  ;   See also:
  ;     The SBCL Manual, Node "Handling of Types"

I guess I could live with this was it not for the fact that it seems to
stop compilation (at least via ASDF using `require') even though it's
only a warning.

Any ideas?

-- 
mvh,
Lars Rune Nøstdal
http://lars.nostdal.org/

From: Christophe Rhodes
Subject: Re: `call-next-method' gives warings
Date: Sun, 28 May 2006 07:16:03 +0000
Message-ID: <sqlksm39ho.fsf@cam.ac.uk>

"Lars Rune Nøstdal" <···········@gmail.com> writes:

> Hi again,
> I'm messing with `call-next-method', but keep getting warnings like
> "asserted type conflicts with derived type" even for very simple cases.
> This is SBCL-0.9.13.
>   [...]
> I guess I could live with this was it not for the fact that it seems to
> stop compilation (at least via ASDF using `require') even though it's
> only a warning.
>
> Any ideas?

Are you compiling with (debug 3) globally?  There's a known issue,
discussed on the SBCL mailing lists, where the instrumentation for the
stepper confuses the type inference engine in the expansion of methods
with call-next-method.

Christophe