Hi! With modern upstream versions, no patch is needed anymore, other than passing the bit width to the makefile (USE_64/USE_X32). This is one line in debian/rules:
diff -Nru nss-3.21/debian/rules nss-3.21/debian/rules --- nss-3.21/debian/rules 2015-08-22 01:51:54.000000000 +0200 +++ nss-3.21/debian/rules 2016-01-15 16:01:14.000000000 +0100 @@ -63,6 +63,7 @@ DIST=$(DISTDIR) \ OBJDIR_NAME=OBJS \ $(and $(filter 64,$(shell dpkg-architecture -qDEB_HOST_ARCH_BITS)),USE_64=1) \ + $(and $(filter x32,$(shell dpkg-architecture -qDEB_HOST_ARCH)),USE_X32=1) \ $(NULL) NSS_TOOLS := \ The test suite does seem to pass as well. (I tested with jessie's debhelper because of #811038.) Please apply! This bug is 3 years old. -- A tit a day keeps the vet away.
diff -Nru nss-3.21/debian/rules nss-3.21/debian/rules --- nss-3.21/debian/rules 2015-08-22 01:51:54.000000000 +0200 +++ nss-3.21/debian/rules 2016-01-15 16:01:14.000000000 +0100 @@ -63,6 +63,7 @@ DIST=$(DISTDIR) \ OBJDIR_NAME=OBJS \ $(and $(filter 64,$(shell dpkg-architecture -qDEB_HOST_ARCH_BITS)),USE_64=1) \ + $(and $(filter x32,$(shell dpkg-architecture -qDEB_HOST_ARCH)),USE_X32=1) \ $(NULL) NSS_TOOLS := \