Soooo... Running from kvm itself it seems that this is reproducible but seems related to some lower level issue (both using sil's command and adding -vga qxl):
journalctl: https://paste.ubuntu.com/p/rdkvsqs8Rs/ (with vga https://paste.ubuntu.com/p/vJsWbvwdDR/) xorg.log: https://paste.ubuntu.com/p/Dt3tMsHgPc/ In both wayland and xorg tries to get a drm device, but that's not set.. Generally when using `-vga gxl` this issue is happening in a randomic way, while it's 100% happening when using the default vga (std, or just not passing it) that is actually using vbe. So, the weird thing here is that with the same kvm vga configurations, we get a working session when just booting from the cdrom. For some reason it looks like that the vbe driver for X isn't even tried in this case; compare Xorg.log above with the one when booting from livecd: https://paste.ubuntu.com/p/QHJsTY2cms/ Then I think this is indeed not a gdm bug per se. ** Changed in: gdm3 (Ubuntu Cosmic) Status: Confirmed => Won't Fix ** Also affects: xorg (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1794280 Title: gdm doesn't start on a fresh installation of Cosmic Desktop Status in gdm3 package in Ubuntu: Won't Fix Status in xorg package in Ubuntu: New Status in gdm3 source package in Cosmic: Won't Fix Status in xorg source package in Cosmic: New Bug description: ubuntu cosmic desktop 20180925 After installation gdm fails to start and there is only a black screen with a blinking cursor on the top left of the screen. gdm3 can be started manually from a tty When this issue happens there is a plymouth crash reported in bug 1794292 ProblemType: Bug DistroRelease: Ubuntu 18.10 Package: gdm3 3.30.0-0ubuntu2 ProcVersionSignature: Ubuntu 4.18.0-7.8-generic 4.18.5 Uname: Linux 4.18.0-7-generic x86_64 ApportVersion: 2.20.10-0ubuntu11 Architecture: amd64 Date: Tue Sep 25 13:54:45 2018 InstallationDate: Installed on 2018-09-25 (0 days ago) InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Alpha amd64 (20180925) ProcEnviron: TERM=linux PATH=(custom, no user) LANG=fr_FR.UTF-8 SHELL=/bin/bash SourcePackage: gdm3 UpgradeStatus: No upgrade log present (probably fresh install) mtime.conffile..etc.gdm3.custom.conf: 2018-09-25T13:49:41.053012 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1794280/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp