Properly support the CABAL_FEATURES="nocabaldep" if user doesn't have dev-haskell/cabal

1 files changed, 17 insertions, 1 deletions

diff --git a/eclass/haskell-cabal.eclass b/eclass/haskell-cabal.eclass
index 151ca89b6de4..fed53721cd45 100644
--- a/eclass/haskell-cabal.eclass
+++ b/eclass/haskell-cabal.eclass
@@ -1,6 +1,6 @@
 # Copyright 1999-2006 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
-# $Header: /var/cvsroot/gentoo-x86/eclass/haskell-cabal.eclass,v 1.16 2009/09/09 18:40:11 kolmodin Exp $
+# $Header: /var/cvsroot/gentoo-x86/eclass/haskell-cabal.eclass,v 1.17 2009/10/28 23:46:16 kolmodin Exp $
 #
 # Original authors: Andres Loeh <kosmikus@gentoo.org>
 #                   Duncan Coutts <dcoutts@gentoo.org>
@@ -113,6 +113,22 @@ cabal-version() {
 			# We're bootstrapping cabal, so the cabal version is the version
 			# of this package itself.
 			_CABAL_VERSION_CACHE="${PV}"
+		elif [[ "${CABAL_FROM_GHC}" ]]; then
+			# We can't assume there's a version of Cabal installed by ebuild as
+			# this might be a first time install of GHC (for packages that
+			# use the shipped Cabal like haskell-updater).
+
+			# The user is likely to only have one version of Cabal, provided
+			# by GHC. Note that dev-haskell/cabal can be a dummy package, only
+			# using the version provided by GHC. If the user has another version
+			# of Cabal too (more recent than the one GHC provides through
+			# dev-haskell/cabal, or possibly older if he used an old
+			# Cabal package) the most recent is used (expected to be the last
+			# one in the ghc-pkg output).
+			_CABAL_VERSION_CACHE="$(ghc-pkg field Cabal version | tail -n 1)"
+
+			# Strip out the "version: " prefix
+			_CABAL_VERSION_CACHE="${_CABAL_VERSION_CACHE#"version: "}"
 		else
 			# We ask portage, not ghc, so that we only pick up
 			# portage-installed cabal versions.