Subject: cabal import parser doesn't support common stanzas
From: "Philip Munksgaard" <[email-masked]>
To: [email-masked]
Date: Thu, 27 May 2021 15:21:43 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

As far as I can tell, the cabal parser for the `guix import` command (https://git.savannah.gnu.org/cgit/guix.git/tree/guix/import/cabal.scm) does not support common stanzas, as specified in the cabal specification (https://cabal.readthedocs.io/en/3.4/cabal-package.html#common-stanzas).

This means that some packages, like "versions" (https://hackage.haskell.org/package/versions-5.0.0/src/versions.cabal) and all depending packages cannot be imported using `guix import hackage versions`:

```
$ guix import hackage versions
Syntax error: unexpected token : common (at line 36, column 0)
Syntax error: unexpected end of input
guix import: error: failed to download cabal file for package 'versions'
```