[Haskell-cafe] Haskell-mode 2.4

[Stefan Monnier]

>> >> First of all, thanks. My Aqua Emacs (on OS X Leopard) hangs when I
>> >> send a command like C-c C-l or C-c C-t to the interpreter (I can quit
>> >> the command using C-g) . Starting the interpreter and using :l from
>> >> inside it works fine. This is using GHC 6.8 (and I think I also tried
>> >> 6.6.) What could be the problem?
>> >>
>> >> I also tried to eval this but it didn't make a difference:
>> >>
>> >> (setq inferior-haskell-find-project-root nil)
>> 
>> > It looks like this is a problem with 6.8.2 as haskell-mode-2.3 has the
>> > same problem? Seems like the commands being sent to the haskell
>> > process never reaches it.
>> 
>> Try can you try to look into the nature of the hang?
>> Is Emacs completely frozen?  Does C-g get you back to something usable?
>> If so, can you set Options => Enter Debugger on Quit, then reproduce the
>> problem than hit C-g and show me the backtrace?
>> If not, can you run Emacs under a debugger and give me a backtrace of
>> when Emacs is frozen?

> Emacs is completely frozen until I press C-g and then it goes back to
> normal (without loading the file). Here's the back trace:

> Debugger entered--Lisp error: (quit)
>   accept-process-output(#<process haskell>)
>   (and (not (re-search-forward comint-prompt-regexp nil t))
> (accept-process-output proc))

So it seems to be waiting for the prompt but can't find it.
If you look at the buffer containing the interactive process, is there
a prompt there?  If not, can you try and figure out why not?
If yes, can you try and figure out why it is not recognized by the
comint-prompt-regexp?


        Stefan