Package: linux-base Version: 4.5 Severity: normal Dear Maintainer,
I recently encountered the following situation while trying to remove the package of a currently running kernel: root@router-foo:~# apt purge linux-image-4.9.0-6-amd64 Reading package lists... Done Building dependency tree Reading state information... Done The following packages will be REMOVED: linux-image-4.9.0-6-amd64* 0 upgraded, 0 newly installed, 1 to remove and 24 not upgraded. After this operation, 193 MB disk space will be freed. Do you want to continue? [Y/n] (Reading database ... 50646 files and directories currently installed.) Removing linux-image-4.9.0-6-amd64 (4.9.88-1+deb9u1) ... Failed to substitute package name in title: 10 at /usr/bin/linux-check-removal line 102, <STDIN> line 1. dpkg: error processing package linux-image-4.9.0-6-amd64 (--remove): subprocess installed pre-removal script returned error exit status 255 Errors were encountered while processing: linux-image-4.9.0-6-amd64 E: Sub-process /usr/bin/dpkg returned an error code (1) Instead of the above error message I expected a dialog asking for confirmation of the removal of the currently running kernel. The same happens reproducible for many hosts (all sharing the same setup). Minimal test: /usr/share/debconf/frontend /usr/bin/linux-check-removal "$(uname -r)" In case of success, the above command leads to a dialog asking for confirmation for removing the currently running kernel. In case of failure, the following error is emitted (resulting in an exitcode 255): Failed to substitute package name in title: 10 at /usr/bin/linux-check-removal line 102, <STDIN> line 1. The problem can be fixed by executing /var/lib/dpkg/info/linux-base.postinst. This results (among others) in the following new section in /var/cache/debconf/config.dat: Name: linux-base/removing-running-kernel Template: linux-base/removing-running-kernel Value: true Owners: linux-base Flags: seen Variables: running = 4.9.0-6-amd64 The problem returns, if the above section is removed from that file. Thus it looks like the script "linux-check-removal" does not handle a situation where the above debconf data is missing. This probably involves very specific circumstances, since the linux-base is widely used and seems to work well for most users. The only specific detail of the problematic environment is probably the fact, that /var/cache is stored on a tmpfs and thus is regularly discarded on every reboot. Cheers, Lars -- System Information: Debian Release: 9.4 APT prefers stable-updates APT policy: (500, 'stable-updates'), (500, 'stable') Architecture: amd64 (x86_64) Kernel: Linux 4.9.0-6-amd64 (SMP w/4 CPU cores) Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE=de_DE.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages linux-base depends on: ii debconf [debconf-2.0] 1.5.61 linux-base recommends no packages. linux-base suggests no packages. -- debconf information: linux-base/removing-title: * linux-base/removing-running-kernel: true
