[slime-devel] Re: Crash course in SLIME RPC debugging (Re: SLDB hangs with CLISP/Cygwin)

[Steven E. Harris]

Luke Gorrie <luke at synap.se> writes:

> I'm tempted to accuse your Emacs of having a broken throw/catch, but
> that's dangerous talk.

Maybe not. Macroexpanding catch/throw reveals that the trow tag is
(symbol-value tag). It seems that by the time that throw gets invoked,
tag has no symbol-value, so an error is thrown (silently) and gets
trapped somewhere.

I've tried all sorts of ways of printing out the tag's value at
various points inside the slime-rex expression. Any attempt to print
the tag's value works, but printing its symbol-value fails.

I have to call it quits on the investigation for tonight, and maybe
I'm barking up the wrong tree, but my best guess right now is that the
throw expression turns out to be a no-op because the destination tag
does not exist. Actually, it's simpler than that: The callback
function fails (again, silently) before throw even executes, because
looking up the tag's symbol-value fails first. Maybe.

Thanks for your help so far.

-- 
Steven E. Harris