+testbinaries 'useless addition to a arch-set' 'i386' 'mips' 'all'
+
+echo 'deb [arch=i386 arch-=all] http://example.org/debian stable rocks' > rootdir/etc/apt/sources.list
+testbinaries 'substract all from arch-set' 'i386'
+
+echo 'deb [arch=i386 arch+=all] http://example.org/debian stable rocks' > rootdir/etc/apt/sources.list
+testbinaries 'useless addition of all' 'i386' 'all'