.o not found

[S.D.Mechveliani]

To my 

>> ghc-5.00.1 -interactive  (binary, linux, i386-unknown)
>>
>> forgets sometimes of existing  Foo.o  module to load and loads
>> instead the interpreted code.
>> A strange effect.
>> Compiled and loaded is a single module  Foo.hs  in the current
>> directory.
>> In such cases I compile  Foo.hs  once more, rerun  ghci
>> and then it finds  Foo.o.
>> How to trace this down if the effect is not always reproducible?


Simon Marlow <simonmar at microsoft.com> writes

> I found one bug recently which could cause this, if you have recursive
> modules and use .hi-boot files. 
> 
> If this isn't the case, you can get more info using the -ddump-hi-diffs
> option, which should give some clue as to why GHC thinks the module
> needs to be recompiled.


My case is the second one. 
And GHC does  not  report of recompilation need.
In simply may load interpreted code instead of .o. 
I added  -ddump-hi-diffs   (to  ghc -c  and to  ghci  lines)
But I cannot reproduce the effect.
Any simplest  Foo.hs  would do. 

-----------------
Serge Mechveliani
mechvel at botik.ru