diff -Nru grub2-2.02~beta2/debian/changelog grub2-2.02~beta2/debian/changelog
--- grub2-2.02~beta2/debian/changelog	2015-05-19 14:31:03.000000000 +0200
+++ grub2-2.02~beta2/debian/changelog	2015-09-11 17:17:56.000000000 +0200
@@ -1,3 +1,13 @@
+grub2 (2.02~beta2-9ubuntu1.4) trusty; urgency=medium
+
+  * Fix the configuration logic to force prompting for
+    installation if grub2 is already present on disk.
+    This is needed to workaround a bug in Lucid that leaves
+    grub-pc/install_devices empty even if grub2 is installed.
+    (LP: #1491894)
+
+ -- Louis Bouchard <louis.bouchard@ubuntu.com>  Fri, 11 Sep 2015 14:34:13 +0200
+
 grub2 (2.02~beta2-9ubuntu1.3) trusty; urgency=medium
 
   * Do not hang headless servers indefinitely on boot after edge case power
diff -Nru grub2-2.02~beta2/debian/postinst.in grub2-2.02~beta2/debian/postinst.in
--- grub2-2.02~beta2/debian/postinst.in	2015-05-13 16:51:57.000000000 +0200
+++ grub2-2.02~beta2/debian/postinst.in	2015-09-11 16:10:10.000000000 +0200
@@ -578,6 +578,24 @@
             done
             db_subst "$question" RAW_CHOICES "$ids"
             db_subst "$question" CHOICES "$descriptions"
+            # When upgrading from a system migrated from Lucid
+            # grub-pc/install_devices may be incorectly empty
+            # we need to check if grub is installed.
+            db_get grub-pc/install_devices
+            if [ -z "$RET" ]; then
+              grub2_is_installed=
+              for device in $ids; do
+                if scan_grub2 "${device%","}"; then
+                  grub2_is_installed=1
+                fi
+              done
+              # If grub2 is installed, force the question
+              # to be asked so we are sure that the most recent
+              # code is installed on the MBR
+              if [ "$grub2_is_installed" ]; then
+                db_fset $question seen false
+              fi
+            fi
             db_input high "$question" || true
             db_go
             db_get "$question"