I believe I've found a bug in the DVD ISO installer logic which affects 11.11 and earlier but in theory could affect 12.x as well.
Description: A default installation of Debian 11.11 (Bullseye) from the official DVD ISO fails with the following error: Installation step failed An installation step failed. You can try to run the failing item again from the menu, or skip it and choose something else. The failing step is: Select and install software This failure occurs during the "Select and install software" stage. The root cause is an attempt to install security updates from the security network repository *even when the user selects the default "No" to using a network mirror*. Steps to Reproduce: 1. Boot the Debian 11.11 DVD ISO on an Internet-connected PC 2. Proceed through the installation process. 3. When prompted "Use a network mirror?", select the default "No". 4. Continue with the installation. 5. The installation will fail at the "Select and install software" step with the aforementioned error. Expected Behavior: The installation should succeed whether the user uses the default "No" to using a network mirror or manually sets a network mirror to use. Observed Behavior: When "No" is selected for the network mirror, the installer still attempts to use the repository http://security.debian.org/debian-security bullseye-security/main. This leads to dependency issues because the DVD media's package versions are older than those required by the security repository updates. The installer then fails because it cannot resolve these dependencies. Workaround: The user must either: 1. Select "Yes" to the "Use a network mirror?" prompt and configure a mirror. 2. Disconnect the machine from the network before starting the installation. These workarounds are not obvious to the user, even after encountering the "Installation step failed" error. Impact: This bug prevents users from performing a default offline installation of Debian 11.11 from the DVD ISO on a network-connected machine. It creates a confusing user experience and may lead users to believe the ISO is faulty. Further Information: This issue highlights a potential disconnect between the intent of the "No" option for network mirrors and the actual installer behavior. IMO, the installer should do one of the following: - Respect the user's choice and perform a purely offline installation when "No" is selected on the network mirror page. - If the user chooses not to use a mirror, check for an internet connection and either: - prompt the user to decide to install security updates, with a warning that this may fail without a mirror. - prompt the user to set a network mirror to avoid potential installation failure. Relevant installation syslog: Jan 31 05:32:59 cdrom-detect: Devices: '/dev/sr0' Jan 31 05:32:59 cdrom-detect: CD-ROM mount succeeded: device=/dev/sr0 fstype=iso9660 Jan 31 05:32:59 kernel: [ 7.306344] ISO 9660 Extensions: Microsoft Joliet Level 3 Jan 31 05:32:59 kernel: [ 7.306752] ISO 9660 Extensions: RRIP_1991A Jan 31 05:32:59 cdrom-detect: Detected CD 'Debian GNU/Linux 11.11.0 "Bullseye" - Official amd64 DVD Binary-1 20240831-14:01' ... Jan 31 05:35:42 apt-setup: warning: /usr/lib/apt-setup/generators/50mirror returned error code 1; discarding output Jan 31 05:35:42 apt-setup: dpkg-divert: warning: diverting file '/sbin/start-stop-daemon' from an Essential package with rename is dangerous, use --no-rename Jan 31 05:35:42 in-target: Get:1 http://security.debian.org/debian-security bullseye-security InRelease [27.2 kB] Jan 31 05:35:42 in-target: Get:2 http://security.debian.org/debian-security bullseye-security/main amd64 Packages [340 kB] Jan 31 05:35:42 in-target: Get:3 http://security.debian.org/debian-security bullseye-security/main Translation-en [221 kB] Jan 31 05:35:43 in-target: Fetched 587 kB in 0s (1,432 kB/s) Jan 31 05:35:43 in-target: Reading package lists... Jan 31 05:35:43 in-target: Jan 31 05:35:43 apt-setup: dpkg-divert: warning: diverting file '/sbin/start-stop-daemon' from an Essential package with rename is dangerous, use --no-rename Jan 31 05:35:43 in-target: Hit:1 http://security.debian.org/debian-security bullseye-security InRelease Jan 31 05:35:43 in-target: Reading package lists... Jan 31 05:35:43 in-target: Jan 31 05:35:43 apt-setup: dpkg-divert: warning: diverting file '/sbin/start-stop-daemon' from an Essential package with rename is dangerous, use --no-rename Jan 31 05:35:43 in-target: Hit:1 http://security.debian.org/debian-security bullseye-security InRelease Jan 31 05:35:43 in-target: Get:2 http://security.debian.org/debian-security bullseye-security/main Sources [233 kB] Jan 31 05:35:43 in-target: Fetched 233 kB in 0s (2,422 kB/s) Jan 31 05:35:43 in-target: Reading package lists... ... Jan 31 05:36:49 in-target: Some packages could not be installed. This may mean that you have Jan 31 05:36:49 in-target: requested an impossible situation or if you are using the unstable Jan 31 05:36:49 in-target: distribution that some required packages have not yet been created Jan 31 05:36:49 in-target: or been moved out of Incoming. Jan 31 05:36:49 in-target: The following information may help to resolve the situation: Jan 31 05:36:49 in-target: Jan 31 05:36:49 in-target: The following packages have unmet dependencies: Jan 31 05:36:49 in-target: gnome-core : Depends: gnome-control-center (>= 1:3.38) but it is not installable Jan 31 05:36:49 in-target: Depends: gnome-user-docs (>= 3.38) but it is not installable Jan 31 05:36:49 in-target: Depends: gnome-sushi (>= 3.34) but it is not installable Jan 31 05:36:49 in-target: Depends: yelp (>= 3.38) but it is not installable Jan 31 05:36:49 in-target: Depends: zenity (>= 3.32) but it is not installable Jan 31 05:36:49 in-target: gnome-online-accounts : Depends: libgoa-backend-1.0-1 (= 3.38.0-3) but it is not installable Jan 31 05:36:49 in-target: Depends: libwebkit2gtk-4.0-37 (>= 2.26) but it is not installable Jan 31 05:36:49 in-target: Recommends: gnome-control-center (>= 3.6.1) but it is not installable Jan 31 05:36:49 in-target: libedataserverui-1.2-2 : Depends: libwebkit2gtk-4.0-37 (>= 2.25.1) but it is not installable Jan 31 05:36:49 in-target: libproxy1-plugin-webkit : Depends: libjavascriptcoregtk-4.0-18 but it is not installable Jan 31 05:36:49 in-target: E: Unable to correct problems, you have held broken packages. Jan 31 05:36:49 in-target: tasksel: apt-get failed (100)
