As indicated in the bug above, a workaround is to add the following value to either /etc/devscripts.conf or ~/.devscripts.conf
DEBUILD_PRESERVE_ENVVARS="DISPLAY" -- debuild fails to use seahorse-agent https://launchpad.net/bugs/78165 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
