[slime-devel] Re: sbcl threads and specials

[Luke Gorrie]

Gábor Melis <mega at hotpop.com> writes:

> The behaviour of SBCL's threads is about to be changed wrt specials. 
> Threads shall no longer inherit the values of specials from the parent. 
> It will be quite similar to other threaded lisps in this regard.

Cool.

> Light testing shows that everything works fine except typing
> 
>   (sb-thread:make-thread (lambda () (break)))
> 
> at the repl does not bring up the debugger anymore. It's because 
> install-debugger in swank.lisp does not set the *invoke-debugger-hook*:
> 
>   (setq sb-ext:*invoke-debugger-hook* #'swank-debugger-hook)

When SWANK:*GLOBAL-DEBUGGER* is T (the default) then
SWANK::INSTALL-DEBUGGER setq's *DEBUGGER-HOOK* globally so that Emacs
will be the default debugger for most errors.

It would be good to make INSTALL-DEBUGGER call a backend function so
that the SBCL backend can set *INVOKE-DEBUGGER-HOOK* too and thus
handle calls to BREAK.