diff -pruN 2.3.3-3/debian/changelog 2.3.3-4/debian/changelog
--- 2.3.3-3/debian/changelog	2018-07-01 18:32:03.000000000 +0000
+++ 2.3.3-4/debian/changelog	2019-02-10 11:25:44.000000000 +0000
@@ -1,3 +1,18 @@
+libseccomp (2.3.3-4) unstable; urgency=medium
+
+  [ Ondřej Nový ]
+  * d/copyright: Change Format URL to correct one
+
+  [ Helmut Grohne ]
+  * Fix FTCBFS: (Closes: #903556)
+    + Multiarchify python Build-Depends.
+    + Annotate cython dependencies with :native for now.
+    + Drop noop dh_auto_build invocations.
+    + Pass a suitable PYTHONPATH for python2.
+    + Pass _PYTHON_SYSCONFIGDATA_NAME for python3.
+
+ -- Felix Geyer <fgeyer@debian.org>  Sun, 10 Feb 2019 12:25:44 +0100
+
 libseccomp (2.3.3-3) unstable; urgency=medium
 
   * Fix FTBFS: Adapt to renamed README file. (Closes: #902767)
diff -pruN 2.3.3-3/debian/control 2.3.3-4/debian/control
--- 2.3.3-3/debian/control	2018-05-09 20:04:08.000000000 +0000
+++ 2.3.3-4/debian/control	2019-02-10 11:13:01.000000000 +0000
@@ -6,10 +6,12 @@ Uploaders: Luca Bruno <lucab@debian.org>
 Build-Depends: debhelper (>= 10~),
                linux-libc-dev,
                dh-python <!nopython>,
-               python-all-dev <!nopython>,
-               python3-all-dev <!nopython>,
-               cython <!nopython>,
-               cython3 <!nopython>
+               python-all-dev:any <!nopython>,
+               libpython-all-dev <!nopython>,
+               python3-all-dev:any <!nopython>,
+               libpython3-all-dev <!nopython>,
+               cython:native <!nopython>,
+               cython3:native <!nopython>
 Standards-Version: 3.9.7
 Homepage: https://github.com/seccomp/libseccomp
 Vcs-Git: https://salsa.debian.org/debian/libseccomp.git
diff -pruN 2.3.3-3/debian/copyright 2.3.3-4/debian/copyright
--- 2.3.3-3/debian/copyright	2018-04-22 21:39:31.000000000 +0000
+++ 2.3.3-4/debian/copyright	2019-02-10 10:58:44.000000000 +0000
@@ -1,4 +1,4 @@
-Format: http://dep.debian.net/deps/dep5
+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
 Upstream-Name: libseccomp
 Source: https://sourceforge.net/projects/libseccomp/
 
diff -pruN 2.3.3-3/debian/rules 2.3.3-4/debian/rules
--- 2.3.3-3/debian/rules	2018-04-30 18:29:48.000000000 +0000
+++ 2.3.3-4/debian/rules	2019-02-10 11:13:01.000000000 +0000
@@ -7,6 +7,8 @@
 # Enable verbose build details.
 export V=1
 
+include /usr/share/dpkg/architecture.mk
+
 %:
 ifeq ($(filter nopython,$(DEB_BUILD_PROFILES)),)
 	dh $@ --with python2,python3
@@ -19,15 +21,12 @@ override_dh_auto_configure:
 	dh_auto_configure -- --enable-python
 
 override_dh_auto_build:
-	dh_auto_build
-	set -e && for pyver in `py3versions -s`; do \
-		dh_auto_build --sourcedirectory=src/python -- PYTHON=$$pyver; \
-	done
+	PYTHONPATH="/usr/lib/python2.7/plat-${DEB_HOST_GNU_TYPE}$${PYTHONPATH:+:$$PYTHONPATH}" dh_auto_build
 
 override_dh_auto_install:
 	dh_auto_install
 	set -e && for pyver in `py3versions -s`; do \
-		dh_auto_install --sourcedirectory=src/python -- PYTHON=$$pyver; \
+		_PYTHON_SYSCONFIGDATA_NAME='_sysconfigdata_m_${DEB_HOST_ARCH_OS}_${DEB_HOST_MULTIARCH}' dh_auto_install --sourcedirectory=src/python -- PYTHON=$$pyver; \
 	done
 endif