diff -Nru grub2-2.02~beta2/debian/changelog grub2-2.02~beta2/debian/changelog
--- grub2-2.02~beta2/debian/changelog	2020-07-20 20:28:33.000000000 +0000
+++ grub2-2.02~beta2/debian/changelog	2020-07-31 04:27:00.000000000 +0000
@@ -1,3 +1,12 @@
+grub2 (2.02~beta2-36ubuntu3.27) xenial; urgency=medium
+
+  * debian/postinst.in: Avoid calling grub-install on upgrade of the grub-pc
+    package, since we cannot be certain that it will install to the correct
+    disk and a grub-install failure will render the system unbootable.
+    LP: #1889556.
+
+ -- Steve Langasek <steve.langasek@ubuntu.com>  Thu, 30 Jul 2020 21:27:00 -0700
+
 grub2 (2.02~beta2-36ubuntu3.26) xenial; urgency=medium
 
   [ Chris Coulson ]
diff -Nru grub2-2.02~beta2/debian/postinst.in grub2-2.02~beta2/debian/postinst.in
--- grub2-2.02~beta2/debian/postinst.in	2019-04-26 19:55:54.000000000 +0000
+++ grub2-2.02~beta2/debian/postinst.in	2020-07-31 04:27:00.000000000 +0000
@@ -475,6 +475,10 @@
         elif running_in_container; then
           # Skip grub-install in containers.
           :
+        elif dpkg --compare-versions "$2" ge 2.02~beta2-36ubuntu3; then
+          # Avoid the possibility of breaking grub on SRU update
+          # due to ABI change
+          :
         elif test -z "$2" || test -e /boot/grub/core.img || \
              test -e /boot/grub/@FIRST_CPU_PLATFORM@/core.img || \
              test "$UPGRADE_FROM_GRUB_LEGACY" || test "$wubi_device"; then