[bug#44518] [PATCH] gnu: Add matterhorn.

[Ricardo Wurmus]

Hi Romain,

> * gnu/packages/haskell-apps.scm (matterhorn): New variable.
> * gnu/packages/haskell-crypto.scm (ghc-crypton, ghc-crypton-x509,
> ghc-crypton-x509-store, ghc-crypton-x509-system,
> ghc-crypton-x509-validation, ghc-tls-1.9): New variables.
> * gnu/packages/haskell-web.scm (ghc-crypton-connection,
> ghc-mattermost-api, ghc-mattermost-api-qc, ghc-modern-uri): New variables.
> * gnu/packages/haskell-xyz.scm (ghc-aspell-pipe, ghc-bimap,
> ghc-checkers, ghc-monad-parallel, ghc-text-zipper-13, ghc-stm-delay,
> ghc-unique, ghc-unix-compat-7, ghc-vty-6, ghc-vty-crossplatform,
> ghc-vty-unix, ghc-hclip, ghc-brick, ghc-brick-skylighting): New variables.

thank you for the patch!  This looks all pretty good.

There are a few minor quibbles:

* Please make one commit for every added package.
* matterhorn: Please sort inputs alphabetically.
* ghc-crypton: please use Texinfo syntax such as @itemize for the list
  of features.
* ghc-crypton-x509: it would be good to know if there is something we
  can do to make tests pass.  If the tests are pointless it would be
  good to record that.  Please also make sure that the description is
  ... descriptive.
* ghc-tls-1.9, ghc-unix-compat-7, ghc-vty-6, ghc-text-zipper-13: Is it
  desirable to have these packages instead of upgrading the existing
  packages?  Is there pending work on the Haskell team branch(es) that
  would make the use of these versioned variants obsolete?
* Please check whether potentially unwanted changes should really be
  included, such as the cosmetic changes to ghc-githash.

I also just found that there's an old patch set for matterhorn; I cc'd
the issue email address.

-- 
Ricardo