Tests passed for me, here's what I did: == 0. setup == $ lxc launch ubuntu-daily:19.10 exim4-merge-test-a Creating exim4-merge-test-a Starting exim4-merge-test-a $ lxc exec exim4-merge-test-a bash root@exim4-merge-test-a:~# add-apt-repository -sy ppa:bryce/exim4-merge-4.92-7 apt update ... ... # apt policy exim4 exim4: Installed: (none) Candidate: 4.92-7ubuntu1~ppa1 == 1. basic install and removal == # apt -y install exim4 ... The following NEW packages will be installed: exim4 exim4-base exim4-config exim4-daemon-light guile-2.2-libs libgc1c2 libgnutls-dane0 libgsasl7 libkyotocabinet16v5 libltdl7 libmailutils5 libmysqlclient20 libntlm0 libpython2.7 libpython2.7-minimal libpython2.7-stdlib libunbound8 mailutils mailutils-common mysql-common 0 upgraded, 20 newly installed, 0 to remove and 3 not upgraded. Need to get 12.9 MB of archives. ... ~# service exim4 status ● exim4.service - LSB: exim Mail Transport Agent Loaded: loaded (/etc/init.d/exim4; generated) Active: active (running) since Mon 2019-05-13 22:14:21 UTC; 42s ago Docs: man:systemd-sysv-generator(8) Tasks: 1 (limit: 4915) Memory: 4.1M CGroup: /system.slice/exim4.service └─3044 /usr/sbin/exim4 -bd -q30m May 13 22:14:21 exim4-merge-test-a systemd[1]: Starting LSB: exim Mail Transport Agent... May 13 22:14:21 exim4-merge-test-a exim4[2796]: * Starting MTA May 13 22:14:21 exim4-merge-test-a exim4[2796]: ...done. May 13 22:14:21 exim4-merge-test-a systemd[1]: Started LSB: exim Mail Transport Agent. root@exim4-merge-test-a:~# echo $? 0 root@exim4-merge-test-a:~# apt -y remove exim4 exim4-base exim4-config The following packages will be REMOVED: exim4 exim4-base exim4-daemon-light exim4-config ... # apt-cache policy exim4 exim4: Installed: (none) Candidate: 4.92-7ubuntu1~ppa1 == 2. simple upgrade == root@exim4-merge-test-a:~# apt-get install exim4-base=4.92-4ubuntu1 ... The following NEW packages will be installed: exim4-base exim4-config 0 upgraded, 2 newly installed, 0 to remove and 3 not upgraded. Need to get 1241 kB of archives. After this operation, 2681 kB of additional disk space will be used. ... root@exim4-merge-test-a:~# apt upgrade -y ... The following NEW packages will be installed: bolt dbus-user-session dconf-gsettings-backend dconf-service fwupd fwupd-signed glib-networking glib-networking-common glib-networking-services gsettings-desktop-schemas libarchive13 libdconf1 libefiboot1 libefivar1 libfwupd2 libgcab-1.0-0 libgpgme11 libgudev-1.0-0 libgusb2 libjson-glib-1.0-0 libjson-glib-1.0-common libproxy1v5 libsmbios-c2 libsoup2.4-1 libxmlb1 sbsigntool secureboot-db The following packages will be upgraded: exim4-base ubuntu-minimal ubuntu-server ubuntu-standard 4 upgraded, 27 newly installed, 0 to remove and 0 not upgraded. Need to get 5047 kB of archives. After this operation, 14.7 MB of additional disk space will be used. ... Setting up secureboot-db (1.4) ... chattr: Permission denied while reading flags on /sys/firmware/efi/efivars/dbx-d719b2cb-3d3a-4596-a3bc-dad00e67656f Filesystem keystore: /usr/share/secureboot/updates/dbx/MS-2016-08-08.bin [7085 bytes] firmware keys: PK: KEK: db: dbx: filesystem keys: PK: KEK: db: dbx: 45c7c8ae750acfbb48fc37527d6412dd644daed8913ccd8a24c94d856967df8e from /usr/share/secureboot/updates/dbx/MS-2016-08-08.bin ... New keys in filesystem: /usr/share/secureboot/updates/dbx/MS-2016-08-08.bin Inserting key update /usr/share/secureboot/updates/dbx/MS-2016-08-08.bin into dbx Can't create key file /sys/firmware/efi/efivars/dbx-d719b2cb-3d3a-4596-a3bc-dad00e67656f: Operation not permitted Error syncing keystore file /usr/share/secureboot/updates/dbx/MS-2016-08-08.bin ... # apt policy exim4-base exim4-base: Installed: 4.92-7ubuntu1~ppa1 Candidate: 4.92-7ubuntu1~ppa1 Version table: *** 4.92-7ubuntu1~ppa1 500 500 http://ppa.launchpad.net/bryce/exim4-merge-4.92-7/ubuntu eoan/main amd64 Packages 100 /var/lib/dpkg/status 4.92-4ubuntu1 500 500 http://archive.ubuntu.com/ubuntu eoan/main amd64 Packages # apt policy exim4-base exim4-base: Installed: 4.92-7ubuntu1~ppa1 Candidate: 4.92-7ubuntu1~ppa1 Version table: *** 4.92-7ubuntu1~ppa1 500 500 http://ppa.launchpad.net/bryce/exim4-merge-4.92-7/ubuntu eoan/main amd64 Packages 100 /var/lib/dpkg/status 4.92-4ubuntu1 500 500 http://archive.ubuntu.com/ubuntu eoan/main amd64 Packages == 3. Autopkgtest == root@exim4-merge-test-a:~# apt install -y autopkgtest ... root@exim4-merge-test-a:~# autopkgtest exim4 -- null ... autopkgtest [22:21:20]: testing package exim4 version 4.92-7ubuntu1~ppa1 autopkgtest [22:21:20]: build not needed autopkgtest [22:21:20]: test daemon: preparing testbed ... System appears safe autopkgtest [22:21:36]: test security: -----------------------] autopkgtest [22:21:37]: test security: - - - - - - - - - - results - - - - - - - - - - security PASS autopkgtest [22:21:37]: @@@@@@@@@@@@@@@@@@@@ summary daemon PASS security PASS