Added back debian/cabal-wrapper, since it still seems needed after all.

debian/cabal-wrapper

@@ -0,0 +1,20 @@
+#!/bin/sh
+# It would be more usual to use:
+#   export CABAL=./Setup
+# But Setup currently has a very bad dependency resolver, and very bad
+# debugging output, and tends to eat all memory and die on small buildds.
+#
+# This should be revisited once Debian has a newer ghc than 7.6.3,
+# and hopefully gets the improved dependency resolver from cabal.
+set -e
+
+# Avoid cabal writing to HOME, and avoid local cabal settings
+# influencing the build.
+HOME=$(mktemp -d)
+export HOME
+
+# Temporary workaround for #763078
+PATH=/usr/lib/llvm-3.4/bin:$PATH
+export PATH
+
+cabal "$@"

debian/changelog

@@ -10,6 +10,7 @@ git-annex (5.20150732) UNRELEASED; urgency=medium
     fscked, or every 5 minutes, whichever comes first. Previously,
     commits were made every 1000 files fscked.
   * Tighten dependency on optparse-applicative to 0.11.0.
+  * Added back debian/cabal-wrapper, since it still seems needed after all.
 
  -- Joey Hess <id@joeyh.name>  Fri, 31 Jul 2015 12:31:39 -0400
 

debian/control

@@ -4,6 +4,7 @@ Priority: optional
 Build-Depends: 
 	debhelper (>= 9),
 	ghc (>= 7.4),
+	cabal-install,
 	libghc-mtl-dev (>= 2.1.1),
 	libghc-missingh-dev,
 	libghc-data-default-dev,

debian/rules

@@ -1,7 +1,6 @@
 #!/usr/bin/make -f
 
-# Avoid using cabal, as it writes to $HOME
-export CABAL=./Setup
+export CABAL=debian/cabal-wrapper
 
 STANDALONE_BUILD=$(shell grep -qe '^Package: git-annex-standalone' debian/control \
                          && echo 1 || echo 0)