Per reference: https://lists.debian.org/debian-devel/2016/06/msg00004.html [...] Adding 'dpkg-architecture -apowerpc -c' in front of the command may help. [...] However from my system: $ echo "Value [$(dpkg-architecture -apowerpc -c)]" Value [] So I am confused now. Is this a bug in debian/rules from src:linux or some other regression in dpkg ?