We are trying to build Debian Packages on virtual slaves which works with Debian Wheezy - but fails with Squeeze. It seems that Squeeze does not like the dpkg-buildpackage parameters that are passed along via debuild:

Unknown signing interface gpg --no-tty --passphrase SOMEPASSPHRASE; please specify -spgp or -sgpg
debuild: fatal error at line 1246:
running debsign failed
[debian-package-builder] Aborting: Command <cd '/tmp/workspace/somepackages/debian' && debuild --check-dirname-level 0 --no-tgz-check -ksomeone@somewhere.de -p'gpg --no-tty --passphrase SOMEPASSPHRASE'> failed 

Environment is:
Jenkins LTS Master (1.509.4) on Debian Wheezy along with the latest Libvirt Slaves and Debian Package Builder Plugins. All Builds are executed on Wheezy and Squeeze virtual machines.