René, You need to have logged in from another machine (via ssh) and run gdb from there. That way gdb won't hang when you stop the shell with Ctrl+C.
Please also remember to try uninstalling the nvidia driver (briefly) so as to compare with nouveau. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1800101 Title: gnome-shell uses 100% CPU Status in gnome-shell package in Ubuntu: Incomplete Bug description: For no obvious reason gnome-shell starts to use 100% CPU. This is a standard install of Ubuntu 18.04 with no special extensions installed. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: gnome-shell 3.28.3-0ubuntu0.18.04.2 ProcVersionSignature: Ubuntu 4.15.0-38.41-generic 4.15.18 Uname: Linux 4.15.0-38-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.20.9-0ubuntu7.4 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Fri Oct 26 10:03:02 2018 DisplayManager: gdm3 ExecutablePath: /usr/bin/gnome-shell InstallationDate: Installed on 2018-08-15 (71 days ago) InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725) SourcePackage: gnome-shell UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1800101/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp