diff -Nru sbcl-2.1.1/debian/changelog sbcl-2.1.1/debian/changelog
--- sbcl-2.1.1/debian/changelog	2021-02-01 20:23:49.000000000 +0000
+++ sbcl-2.1.1/debian/changelog	2021-02-03 20:37:00.000000000 +0000
@@ -1,3 +1,10 @@
+sbcl (2:2.1.1-2) unstable; urgency=medium
+
+  * skip-stack-scan-precise-gencgc.patch: new patch from upstream, fixes
+    FTBFS on arm64
+
+ -- Sébastien Villemot <sebastien@debian.org>  Wed, 03 Feb 2021 21:37:00 +0100
+
 sbcl (2:2.1.1-1) unstable; urgency=medium
 
   * New upstream release
diff -Nru sbcl-2.1.1/debian/patches/series sbcl-2.1.1/debian/patches/series
--- sbcl-2.1.1/debian/patches/series	2020-12-09 12:40:35.000000000 +0000
+++ sbcl-2.1.1/debian/patches/series	2021-02-03 20:34:45.000000000 +0000
@@ -5,3 +5,4 @@
 disable-timer-test.patch
 skip-some-autopkgtests.patch
 disable-fcb-threads-test.patch
+skip-stack-scan-precise-gencgc.patch
diff -Nru sbcl-2.1.1/debian/patches/skip-stack-scan-precise-gencgc.patch sbcl-2.1.1/debian/patches/skip-stack-scan-precise-gencgc.patch
--- sbcl-2.1.1/debian/patches/skip-stack-scan-precise-gencgc.patch	1970-01-01 00:00:00.000000000 +0000
+++ sbcl-2.1.1/debian/patches/skip-stack-scan-precise-gencgc.patch	2021-02-03 20:36:39.000000000 +0000
@@ -0,0 +1,22 @@
+Description: Skip stack scan in precise gencgc's save-lisp-and-die
+ Fixes FTBFS on arm64:
+ <long description that can span multiple lines, optional>
+Origin: upstream, https://sourceforge.net/p/sbcl/sbcl/ci/b32d134759519fdf5b30699b85f9d99a7e74dc95/
+Bug: https://bugs.launchpad.net/sbcl/+bug/1914235
+Last-Update: 2021-02-03
+---
+This patch header follows DEP-3: http://dep.debian.net/deps/dep3/
+--- a/src/runtime/gencgc.c
++++ b/src/runtime/gencgc.c
+@@ -3654,9 +3654,9 @@ garbage_collect_generation(generation_in
+ #if GENCGC_IS_PRECISE
+     /*
+      * If not x86, we need to scavenge the interrupt context(s) and the
+-     * control stack.
++     * control stack, unless in final GC then don't.
+      */
+-    {
++    if (conservative_stack) {
+         struct thread *th;
+         for_each_thread(th) {
+             scavenge_interrupt_contexts(th);