diff -Nru glm-0.9.9.8+ds/debian/changelog glm-0.9.9.8+ds/debian/changelog
--- glm-0.9.9.8+ds/debian/changelog	2020-05-02 18:41:19.000000000 +0000
+++ glm-0.9.9.8+ds/debian/changelog	2021-10-12 12:52:57.000000000 +0000
@@ -1,3 +1,9 @@
+glm (0.9.9.8+ds-1ubuntu1) impish; urgency=medium
+
+  * Add d/p/tests-no-optimization.patch, to fix FTBFS with GCC-11, LP: #1946750
+
+ -- Lukas Märdian <slyon@ubuntu.com>  Tue, 12 Oct 2021 14:52:57 +0200
+
 glm (0.9.9.8+ds-1) unstable; urgency=medium
 
   * Team Upload
diff -Nru glm-0.9.9.8+ds/debian/control glm-0.9.9.8+ds/debian/control
--- glm-0.9.9.8+ds/debian/control	2020-05-02 18:12:35.000000000 +0000
+++ glm-0.9.9.8+ds/debian/control	2021-10-12 12:52:57.000000000 +0000
@@ -1,5 +1,6 @@
 Source: glm
-Maintainer: Debian Science Maintainers <debian-science-maintainers@lists.alioth.debian.org>
+Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
+XSBC-Original-Maintainer: Debian Science Maintainers <debian-science-maintainers@lists.alioth.debian.org>
 Uploaders: Guus Sliepen <guus@debian.org>
 Section: libs
 Priority: optional
diff -Nru glm-0.9.9.8+ds/debian/patches/series glm-0.9.9.8+ds/debian/patches/series
--- glm-0.9.9.8+ds/debian/patches/series	1970-01-01 00:00:00.000000000 +0000
+++ glm-0.9.9.8+ds/debian/patches/series	2021-10-12 12:35:17.000000000 +0000
@@ -0,0 +1 @@
+tests-no-optimization.patch
diff -Nru glm-0.9.9.8+ds/debian/patches/tests-no-optimization.patch glm-0.9.9.8+ds/debian/patches/tests-no-optimization.patch
--- glm-0.9.9.8+ds/debian/patches/tests-no-optimization.patch	1970-01-01 00:00:00.000000000 +0000
+++ glm-0.9.9.8+ds/debian/patches/tests-no-optimization.patch	2021-10-12 12:52:16.000000000 +0000
@@ -0,0 +1,19 @@
+Description: Fix FTBFS (unit-tests) with GCC-11
+Author: Lukas Märdian <slyon@ubuntu.com>
+Origin: vendor, Ubuntu
+Bug: https://github.com/g-truc/glm/pull/1087
+Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/glm/+bug/1946750
+Forwarded: https://github.com/g-truc/glm/pull/1087
+Last-Update: 2021-10-12
+
+--- glm-0.9.9.8+ds.orig/test/CMakeLists.txt
++++ glm-0.9.9.8+ds/test/CMakeLists.txt
+@@ -206,7 +206,7 @@ elseif(CMAKE_CXX_COMPILER_ID MATCHES "GN
+ 		message("GLM: GCC - ${CMAKE_CXX_COMPILER_ID} compiler")
+ 	endif()
+ 
+-	add_compile_options(-O2)
++	add_compile_options(-O0)
+ 	add_compile_options(-Wno-long-long)
+ 
+ elseif(CMAKE_CXX_COMPILER_ID MATCHES "Intel")