[slime-devel] sbcl threads and specials

[Gábor Melis]

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.

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)

Until now the value of *invoke-debugger-hook* established by a let 
binding was inherited by threads, but that's no longer be the case.

Let me know if there are other problems lurking behind the surface with 
the new scheme.

Cheers, Gábor