Package: src:xcffib Version: 0.4.2-1 Severity: normal Tags: patch xcffib is using cffi is out-of-line mode, which means it doesn't actually import cffi at runtime, only the cffi-backend. So, it doesn't need to Depend on python-cffi.
Patch attached. SR
diff -Nru xcffib-0.4.2/debian/control xcffib-0.4.2/debian/control --- xcffib-0.4.2/debian/control 2016-05-29 08:25:32.000000000 -0400 +++ xcffib-0.4.2/debian/control 2016-08-01 11:07:20.000000000 -0400 @@ -48,7 +48,6 @@ Package: python-xcffib Architecture: alpha amd64 arm64 armel armhf i386 mipsel ppc64el sh4 x32 Depends: python-six - , python-cffi (>= 1.1.0) , libxcb1 , ${misc:Depends} , ${shlibs:Depends} @@ -66,7 +65,6 @@ Package: python3-xcffib Architecture: any Depends: python3-six, - , python3-cffi (>= 1.1.0) , libxcb1 , ${misc:Depends} , ${shlibs:Depends}