[arch-dev-public] [Draft] - News announcement for GHC 7.8.2

[Thomas Dziedzic]

On Tue, Apr 29, 2014 at 11:23 PM, Gaetan Bisson <bisson at archlinux.org>wrote:
>
> > GHC 7.8.2 requires user intervention and brings changes.
>                                            ^^^^^^^^^^^^^^
> Any chance you could be more specific? May I suggest something like
> "Upgrading to, and managing Haskell packages with GHC 7.8.2"?


 Thanks for this, I will use this title instead


> > Since ghc 7.8.2 does not replace
> > haskell-transformers 0.3.0.0
>
> Simple question: why isn't that the case?


The ghc in [testing] provides=('haskell-transformers=0.3.0.0') and
replaces=('haskell-transformers<0.3.0.0') but in repos, it is at 0.3.0.0 so
this replaces is not enough.
I caught this replaces only after everything was built and moved to
[testing]. Changing the replaces to replaces=('haskell-transformers') would
require recompiling every package that was recompiled as part of the todo.

updated Draft:

Title:
Upgrading to, and managing Haskell packages with GHC 7.8.2

Content:
The package haskell-transformers was previously a separate package but is
now provided with ghc 7.8.2. Since ghc 7.8.2 does not replace
haskell-transformers 0.3.0.0, the user must run the following command prior
to upgrading the packages:

pacman -Rcs haskell-transformers

Don't forget to reinstall the packages that got removed from the above
command after upgrading ghc.

Changes that come with the release include:
1) Moving every package that is not ghc or cabal-install to [community].
This will allow better support of the core common haskell libraries since I
do not actually use these packages due to cabal-install.

2) The valid paths that a user can take to install packages are the
following:

 a) Using cabal-install to install haskell packages. This allows the user
to access every haskell package in hackage. The problem is that you are now
using packages that are managed outside of pacman. This is usually the best
option if you are developing any haskell applications due to the new
sandboxing that cabal-install 1.18 has introduced.

 b) Using pacman to install haskell packages. This allows the user to have
access to a small subset of hackage packages which are known to work on
archlinux and are usually good enough for non haskell developers.

 c) Using an unofficial repository called Arch Haskell. You could find more
information about the repository at the following page:
https://github.com/archhaskell/habs/blob/master/README.md