GDM3 does not start if SDDM is installed (18.04)

[Raul Dias]

After upgrading my office machines to 18.04, some machines did not start the GDM3.

After some testing the problem was that the ones that it did not work, had SDDM installed too (KDE environment in those machines).

The upgrade were from 17.10 and 16.04.

Note that reistalling sddm, gdm3, lightdm, dpkg-reconfigure gdm3, none worked.

On gdm3 side: systemctl is-active gdm3 reports static (which might be the problem).

After removing sddm and rebooting, everything worked as expected.
---
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CurrentDesktop: KDE
DistroRelease: Ubuntu 18.04
InstallationDate: Installed on 2014-05-12 (1458 days ago)
InstallationMedia: Error: [Errno 13] Permission denied: '/var/log/installer/media-info'
NonfreeKernelModules: nvidia_modeset nvidia
Package: sddm
PackageArchitecture: amd64
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Tags: bionic
Uname: Linux 4.15.0-20-generic x86_64
UpgradeStatus: Upgraded to bionic on 2018-04-27 (12 days ago)
UserGroups: adm cdrom dip lpadmin lxd plugdev sambashare sudo
_MarkForUpload: True

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command only once, as it will automatically gather debugging information, in a terminal:

apport-collect 1769969

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[Raul Dias (rsd)]

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[Raul Dias (rsd)]

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[Raul Dias (rsd)]

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