[slime-devel] Re: make swank safe if loaded into an image with an older version of swank in the image

[Luis Oliveira]

Marco Baringer <mb at bese.it> writes:
>   It can happen (though i admit it's a rare occurance) that you build an
>   image with swank, update swank and then try to load swank into the
>   existing image. hard to debug/understand errors ensue, this simple
>   patch protects against that.
[...]
> Index: swank-loader.lisp
[...]
> +(eval-when (:compile-toplevel :load-toplevel :execute)
> +  (when (find-package :swank)
> +    (delete-package :swank)
> +    (delete-package :swank-io-package)
> +    (delete-package :swank-loader)
> +    (delete-package :swank-backend)))
> +
[...]

This patch seems to break loading swank through ASDF from within SLIME.
(I came across this while loading another system that depends on swank.)

Emacs just hangs and pressing C-g gets me the following message printed
onto the repl buffer:

  debugger invoked on a SIMPLE-TYPE-ERROR: *PACKAGE* can't be a deleted
  package: *PACKAGE* has been reset to #<PACKAGE "COMMON-LISP-USER">.

Reverting the patch fixes this.

-- 
Luís Oliveira
http://student.dei.uc.pt/~lmoliv/