ghc --make, recompilation problems? (was: GHC 6.2)

[Claus Reinke]

>We're removing a lot of old/deprecated stuff in 6.2, so I want to be sure we haven't broken 
>anything before doing the release.  The best estimate I can give is 4-6 weeks, but it could be 
>sooner if things settle down quickly.

talking about broken things: I've been reluctant to mention it so far,
because I can't even give a reproducable example, and the problem 
only occurs on very large projects, so without a clue as to what 
might cause it, I certainly couldn't narrow down such an example, 
should I manage to pin down one. 

there seems to be a problem in ghc --make's recompilation dependency
checks, which means that recompilation might produce inconsistent
executables. the usual effect is a problem-free rebuild, followed by
inexplicable crashes of the executable. removing the .hi/.o files and
calling ghc --make again reliably solves the problem, which is why
I suspect recompilation-only dependency checks (type/class changes
not propagated to dependent modules?).

sorry about this rather useless piece of information, but perhaps 
other people on this list have other parts of the puzzle, and it would
be nice to get rid of this (haskell programs don't crash like this!-).

cheers,
claus