事件顺序如下。计算机打开，用户 A 登录 Ubuntu。一段时间后，屏幕保护程序启动。用户 B 出现并从锁定的屏幕上选择“以其他用户身份登录”。Ubuntu 立即崩溃并显示此屏幕（见下面的屏幕截图）。此时计算机完全锁定，不再响应键盘或鼠标的输入。
我几周前才安装 Ubuntu，所以它还比较新。上述问题大约有一半时间会发生，其他时间选择“以其他用户身份登录”时，它就可以正常工作。
以下是崩溃时 /var/log/syslog 的内容...
Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (**) Option "fd" "21" Mar 3 20:34:31 rgoscar-desktop kernel: [48471.682629] rfkill: input handler enabled Mar 3 20:34:31 rgoscar-desktop kernel: [48471.791031] show_signal_msg: 27 callbacks suppressed Mar 3 20:34:31 rgoscar-desktop kernel: [48471.791034] gnome-shell[927]: segfault at 91 ip 0000000000000091 sp 00007ffd59787138 error 14 Mar 3 20:34:31 rgoscar-desktop kernel: [48471.791038] Code: Bad RIP value. Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) event1 - Power Button: device removed Mar 3 20:34:31 rgoscar-desktop gsd-color[1140]: failed to set screen _ICC_PROFILE: Failed to open file “/home/rgoscar/.local/share/icc/edid-91a77f3fba628619db71e250f829f8d8.icc”: Permission denied Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (**) Option "fd" "24" Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) event4 - Video Bus: device removed Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (**) Option "fd" "25" Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) event0 - Power Button: device removed Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (**) Option "fd" "26" Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) event2 - Dell Dell Smart Card Reader Keyboard: device removed Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (**) Option "fd" "27" Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) event3 - Logitech M325: device removed Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (**) Option "fd" "28" Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (**) Option "fd" "28" Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) event14 - Hauppauge WinTV-dualHD 01595 ATSC/QAM: device removed Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) AIGLX: Suspending AIGLX clients for VT switch Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) systemd-logind: got pause for 226:0 Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) systemd-logind: got pause for 13:67 Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) systemd-logind: got pause for 13:68 Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) systemd-logind: got pause for 13:65 Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) systemd-logind: got pause for 13:64 Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) systemd-logind: got pause for 13:78 Mar 3 20:34:31 rgoscar-desktop /usr/lib/gdm3/gdm-x-session[1309]: (II) systemd-logind: got pause for 13:66 Mar 3 20:34:32 rgoscar-desktop gnome-session[909]: gnome-session-binary[909]: WARNING: Application 'org.gnome.Shell.desktop' killed by signal 11 Mar 3 20:34:32 rgoscar-desktop org.gnome.Shell.desktop[927]: (EE) Mar 3 20:34:32 rgoscar-desktop org.gnome.Shell.desktop[927]: Fatal server error: Mar 3 20:34:32 rgoscar-desktop org.gnome.Shell.desktop[927]: (EE) failed to read Wayland events: Broken pipe Mar 3 20:34:32 rgoscar-desktop org.gnome.Shell.desktop[927]: (EE) Mar 3 20:34:32 rgoscar-desktop gnome-session-binary[909]: Unrecoverable failure in required component org.gnome.Shell.desktop Mar 3 20:34:32 rgoscar-desktop gnome-session-binary[909]: WARNING: Application 'org.gnome.Shell.desktop' killed by signal 11 Mar 3 20:34:32 rgoscar-desktop gsd-power[1156]: Error setting property 'PowerSaveMode' on interface org.gnome.Mutter.DisplayConfig: GDBus.Error:org.freedesktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying (g-dbus-error-quark, 4) Mar 3 20:34:32 rgoscar-desktop gsd-color[1594]: failed to connect to device: Failed to connect to missing device /org/freedesktop/ColorManager/devices/xrandr_ViewSonic_Corporation_VE710b_2_P1Q042101664_gdm_121 Mar 3 20:34:32 rgoscar-desktop at-spi-bus-launcher[1081]: XIO: fatal IO error 11 (Resource temporarily unavailable) on X server ":1024" Mar 3 20:34:32 rgoscar-desktop at-spi-bus-launcher[1081]: after 21 requests (21 known processed) with 0 events remaining. Mar 3 20:34:32 rgoscar-desktop systemd[1]: Stopping User Manager for UID 121... Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopping D-Bus User Message Bus... Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopping sandboxed app permission store... Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopping Sound Service... Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopped target Default. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopping Accessibility services bus... Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopped sandboxed app permission store. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopped D-Bus User Message Bus. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopped Accessibility services bus. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopped Sound Service. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopped target Basic System. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopped target Paths. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopped Pending report trigger for Ubuntu Report. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopped target Sockets. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Closed GnuPG cryptographic agent and passphrase cache. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Closed D-Bus User Message Bus Socket. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Closed GnuPG cryptographic agent and passphrase cache (restricted). Mar 3 20:34:32 rgoscar-desktop systemd[887]: Closed GnuPG network certificate management daemon. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Closed GnuPG cryptographic agent (ssh-agent emulation). Mar 3 20:34:32 rgoscar-desktop systemd[887]: Closed GnuPG cryptographic agent and passphrase cache (access for web browsers). Mar 3 20:34:32 rgoscar-desktop systemd[887]: Closed REST API socket for snapd user session agent. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Stopped target Timers. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Closed Sound System. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Reached target Shutdown. Mar 3 20:34:32 rgoscar-desktop systemd[887]: Starting Exit the Session... Mar 3 20:34:32 rgoscar-desktop systemd[887]: Received SIGRTMIN+24 from PID 4708 (kill). Mar 3 20:34:32 rgoscar-desktop systemd[1]: Stopped User Manager for UID 121. Mar 3 20:34:32 rgoscar-desktop systemd[1]: Removed slice User Slice of gdm.
答案1
安装该lightdm软件包就可以解决问题。
sudo apt install lightdm