--- ghc-bin-6.4.2.environment.orig	2008-02-28 21:49:45.000000000 +0100
+++ ghc-bin-6.4.2.environment	2008-02-28 21:49:37.000000000 +0100
@@ -2790,4 +2790,7 @@
 ghc-package_pkg_prerm () 
 { 
+    local old_extglob=$(shopt -p extglob)
+    shopt -s extglob
     ghc-unregister-pkg "$(ghc-localpkgconf)"
+    eval $old_extglob
 }