I periodically build a debian/stretch/amd64 system and all is OK until september 2016. I have some packages .deb into into directory config/packages.chroot
After september 2016 live build fail. Log: [2016-11-28 21:44:09] lb chroot_apt install P: Configuring file /etc/apt/apt.conf [2016-11-28 21:44:10] lb chroot_archives chroot install P: Configuring file /etc/apt/sources.list gpg: WARNING: unsafe permissions on homedir '/root/.gnupg' gpg: no default secret key: No secret key gpg: signing failed: No secret key P: Begin unmounting filesystems... P: Saving caches... If config/packages.chroot is empty all is ok. Thanks for your help.
