I've encountered the following problem when using debconf to configure a package in Ubuntu 16.04 during installation.More precisely, the package uses debconf to save configurations files, and right after, in the postinst script, a service is started. This service also uses a debconf module to load the configurations saved in the previous step.However, the service started with systemd fails with the error:debconf: DbDriver config: /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailableFrom what I could find, dpkg is still accessing this file with the debconf frontend, and the service crashes when it tries to start another frontend (the environmental variable DEBIAN_HAS_FRONTEND is not passed to the service). I have tried forcing the env variable DEBIAN_HAS_FRONTEND in the script, but then other errors appear. I think I should force starting the daemon after the dpkg process has ended, and debconf has already finished, any ideas? 
Debconf error in system with systemd
debian;systemd;debconf