[Haskell-cafe] problems installing latest parsec
michael at schmong.org
Tue Nov 2 20:31:35 EDT 2010
thanks, it seems to be fine now.
On Tue, Nov 2, 2010 at 5:04 PM, Daniel Fischer <daniel.is.fischer at web.de> wrote:
> On Wednesday 03 November 2010 00:46:13, Michael Litchard wrote:
>> Here's what cabal says I have installed
>> * parsec
>> Synopsis: Monadic parser combinators
>> Latest version available: 3.1.0
>> Latest version installed: 18.104.22.168
>> Homepage: http://www.cs.uu.nl/~daan/parsec.html
>> License: BSD3
>> but here is what happens when I try to upgrade
>> cabal upgrade parsec
>> Resolving dependencies...
>> No packages to be installed. All the requested packages are already
>> installed. If you want to reinstall anyway then use the --reinstall
>> mlitchard at kether:~/projects/perf/autoperf/session_creator$
>> Any clues as to what I can try next to fix things would be appreciated.
> $ cabal install parsec-3.1.0
> There's a preferred version constraint on parsec, so by default cabal
> installs parsec-2 rather than parsec-3, you have to tell it explicitly to
> install parsec-3. It might be necessary to tell cabal to use parsec-3 also
> when installing other packages that depend on parsec,
> $ cabal install --constraint="parsec == 3.1.0" whatever
> should do the trick then (if it doesn't use the --preference flag instead
> of --constraint).
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