Hi John,
I just stumbled on this issue while trying to compile turbinado with
the haskell platform / ghc 6.10.4. I got past it by manually editing
back in the time definitions, but just wondering if there was an
official resolution. Thanks,
Warren
On Oct 13, 2009, at 6:48 AM, John Goerzen wrote:
Hugo Gomes wrote:
The Glorious Glasgow Haskell Compilation System, version 6.10.4
with old-time-1.0.0.2 and time-1.1.2.4
This is a standard haskell platform on a windows xp. Cabal install
didn't work complaining about missing instances of typeable for posix
time and other datatypes, yet, after removing the macros (thus,
adding
those instances), hdbc and convertible compiled and installed fine.
Removing the macros might be a bit overkill, probably finetuning
them so
that they add only the necessary instances for typeable in ghc > 610
might be a better solution.
I'm going to CC haskell-cafe on this because I am confused.
Hugo, can you confirm what version of convertible you have?
Back on May 21, I started a thread [1] on haskell-cafe complaining
that
GHC 6.10.3 included a newer time that included instances of Typeable
for
NominalDiffTime and UTCTime. This broke my code, which had manually
defined instances for these types, as they were needed. Things got
complicated, as only time's minor version number got incremented
(x.x.x.Y) [2]. Cabal can't test against that version number.
I wanted my code to work with old and new versions of GHC. Since
testing against the version of time was impossible, I did the next
best
thing: tested against the version of GHC.
#if __GLASGOW_HASKELL__ >= 610
-- instances added in GHC 6.10.3
#else
instance Typeable NominalDiffTime where
typeOf _ = mkTypeName "NominalDiffTime"
instance Typeable UTCTime where
typeOf _ = mkTypeName "UTCTime"
#endif
Also, in the .cabal, there is a build-depends on time>=1.1.2.4.
Now, that would break for GHC 6.10.1 and 6.10.2 users, but will work
for
6.10.3 and above, or 6.8 and below. Or so I thought.
Now I'm getting complaints from people using 6.10.4 saying that there
are now missing instances of Typeable with time 1.1.2.4.
1) Did the Typeable instances get dropped again from time?
2) What exactly should I do so this library compiles on GHC 6.8 and
6.10.x?
I'm looking at the darcs repo for time and don't see the instances
ever
getting dropped.
[1] http://osdir.com/ml/haskell-cafe@haskell.org/2009-05/msg00982.html
[2] http://osdir.com/ml/haskell-cafe@haskell.org/2009-05/msg00985.html
.... later addendum ....
so it appears that what's happening here is that GHC 6.10.3 extralibs
included time 1.1.3, but then haskell-platform standardized on
1.1.2.4.
This is pretty annoying -- that haskell-platform would standardize
on a
version older than what shipped with a GHC release -- but I guess I
can
work around it by restricting my build-dep to be time < 1.1.3 and
re-adding the instances.
Does this sound right?
On Tue, Oct 13, 2009 at 2:51 AM, John Goerzen <jgoer...@complete.org
<mailto:jgoer...@complete.org>> wrote:
Hugo Gomes wrote:
Hi,
convertible and hdbc packages fail to compile in my standard
instalation
of the haskell platform. I think this has to do with those "if ghc
>=
610" macros on the typeable instances for some datatypes. I
removed them
and now they work fine...
What version of GHC and time do you have?
-- John
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