I have created a custom ostree and iso based on Fedora Silverblue 36, it does not contain any desktop environment just boot to console and start sway.
If I install using the official Silverblue iso then change to my custom ostree is works as expected, instead if I install from scratch using my custom iso (same ostree) it does not prompt to create any user so I am stuck to the console with no possibility to login.
During the installation process I can only pick the installation destination.
We talked about that on #sway:fedoraproject.org today, you can check the matrix room logs for lots of additional details.
Anaconda has a set of different profiles, which are defining the installer behavior.
The profile is chosen depending on the /etc/os-release contents in the installer image. E.g. if grep VARIANT_ID /etc/os-release in the installer shell returns workstation or silverblue, fedora-workstation.conf or fedora-silverblue.conf will be applied correspondingly.
The important difference between the profiles is the approach to an initial setup - all Gnome variants remove User/Password screens from the installer and run gnome-initial-setup on the first boot instead. So my best guess is that your custom iso image picks one of the Gnome profiles.
In the installer shell, you can check /tmp/anaconda.log to confirm this:
DBG core.configuration.profile: Detecting a profile for ID=fedora, VARIANT_ID=silverblue.
INF core.configuration.profile: The 'fedora-silverblue' profile is detected.
INF core.configuration.anaconda: Load the 'fedora-silverblue' profile configuration.
How to fix that? Simple - build your custom iso with the fedora-release-xxx subpackage that matches with one of the good profiles, e.g. fedora-release-kinoite or just generic fedora-release. With lorax, this is defined by the --variant commandline argument, and I expect that the default fedora-release would be selected if you don’t set any variant.