diff -Nru firefox-89.0+build2/debian/changelog firefox-89.0+build2/debian/changelog
--- firefox-89.0+build2/debian/changelog	2021-05-28 10:34:25.000000000 +0000
+++ firefox-89.0+build2/debian/changelog	2021-05-31 21:32:37.000000000 +0000
@@ -1,3 +1,10 @@
+firefox (89.0+build2-0ubuntu0.20.04.2) focal; urgency=medium
+
+  * Fix FTBFS on ppc64el (LP: #1930315):
+    - debian/patches/ppc64el-clang10-no-fast-math.patch
+
+ -- Olivier Tilloy <olivier.tilloy@canonical.com>  Mon, 31 May 2021 23:32:37 +0200
+
 firefox (89.0+build2-0ubuntu0.20.04.1) focal; urgency=medium
 
   * New upstream release (89.0+build2)
diff -Nru firefox-89.0+build2/debian/patches/ppc64el-clang10-no-fast-math.patch firefox-89.0+build2/debian/patches/ppc64el-clang10-no-fast-math.patch
--- firefox-89.0+build2/debian/patches/ppc64el-clang10-no-fast-math.patch	1970-01-01 00:00:00.000000000 +0000
+++ firefox-89.0+build2/debian/patches/ppc64el-clang10-no-fast-math.patch	2021-05-31 21:31:58.000000000 +0000
@@ -0,0 +1,18 @@
+Description: do not build SWGL with -ffast-math on ppc64el with clang <= 10 (bionic and focal), because the compiler hangs forever
+Bug-Ubuntu: https://launchpad.net/bugs/1930315
+Author: Olivier Tilloy <olivier.tilloy@canonical.com>
+
+--- a/gfx/wr/swgl/build.rs
++++ b/gfx/wr/swgl/build.rs
+@@ -191,8 +191,11 @@ fn main() {
+         } else if tool.is_like_clang() {
+             // gcc only supports -mrecip=none on some targets so to keep
+             // things simple we don't use -ffast-math with gcc at all
++            let target = std::env::var("TARGET").unwrap();
++            if !target.starts_with("powerpc64") {
+             build.flag("-ffast-math")
+                  .flag("-mrecip=none");
++            }
+         }
+     }
+ 
diff -Nru firefox-89.0+build2/debian/patches/series firefox-89.0+build2/debian/patches/series
--- firefox-89.0+build2/debian/patches/series	2021-03-23 05:57:32.000000000 +0000
+++ firefox-89.0+build2/debian/patches/series	2021-05-31 21:32:13.000000000 +0000
@@ -16,3 +16,4 @@
 armhf-clang-no-integrated-as-for-neon.patch
 armhf-do-not-build-qcms-with-neon.patch
 libpixman-disable-vmx.patch
+ppc64el-clang10-no-fast-math.patch