我刚刚启动电脑，无法选择 Ubuntu 的默认环境。如果我选择它，我会看到默认和 Xorg 都被选中，并且它使用 Xorg 运行。此外，我在使用某些 Gnome 扩展时遇到了问题。知道这可能是为什么吗？我该如何追踪错误？
几天前检查了 /var/log/apt/history.log 并发现了这一点：
Commandline: aptdaemon role='role-commit-packages' sender=':1.129'
Install: linux-signed-image-4.13.0-17-generic:amd64 (4.13.0-17.20, automatic), linux-image-extra-4.13.0-17-generic:amd64 (4.13.0-17.20, automatic), linux-headers-4.13.0-17-generic:amd64 (4.13.0-17.20, automatic), linux-headers-4.13.0-17:amd64 (4.13.0-17.20, automatic), linux-image-4.13.0-17-generic:amd64 (4.13.0-17.20, automatic)
Upgrade: gnome-control-center-data:amd64 (1:3.26.1-0ubuntu4, 1:3.26.1-0ubuntu5), gnome-session:amd64 (3.26.1-0ubuntu5, 3.26.1-0ubuntu6), libcups2:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), libcups2:i386 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), linux-headers-generic:amd64 (4.13.0.16.17, 4.13.0.17.18), gnome-session-common:amd64 (3.26.1-0ubuntu5, 3.26.1-0ubuntu6), gir1.2-gtk-3.0:amd64 (3.22.24-0ubuntu1, 3.22.25-0ubuntu0.1), unity-session:amd64 (3.26.1-0ubuntu5, 3.26.1-0ubuntu6), gir1.2-mutter-1:amd64 (3.26.1-2ubuntu1, 3.26.2-0ubuntu0.1), gnome-control-center:amd64 (1:3.26.1-0ubuntu4, 1:3.26.1-0ubuntu5), linux-libc-dev:amd64 (4.13.0-16.19, 4.13.0-17.20), libapt-inst2.0:amd64 (1.5, 1.5.1), sane-utils:amd64 (1.0.27-1~experimental2ubuntu1, 1.0.27-1~experimental2ubuntu2.1), libwbclient0:amd64 (2:4.6.7+dfsg-1ubuntu3, 2:4.6.7+dfsg-1ubuntu3.1), libgtk-3-common:amd64 (3.22.24-0ubuntu1, 3.22.25-0ubuntu0.1), libraw16:amd64 (0.18.2-2, 0.18.2-2ubuntu0.1), linux-image-generic:amd64 (4.13.0.16.17, 4.13.0.17.18), apt:amd64 (1.5, 1.5.1), libgtk-3-0:amd64 (3.22.24-0ubuntu1, 3.22.25-0ubuntu0.1), xul-ext-ubufox:amd64 (3.4-0ubuntu0.17.04.1, 3.4-0ubuntu1.17.10.1), ubuntu-advantage-tools:amd64 (10, 10ubuntu0.17.10.1), language-selector-common:amd64 (0.180, 0.180.1), linux-signed-image-generic:amd64 (4.13.0.16.17, 4.13.0.17.18), lshw:amd64 (02.18-0.1ubuntu3, 02.18-0.1ubuntu4), libmutter-1-0:amd64 (3.26.1-2ubuntu1, 3.26.2-0ubuntu0.1), ubuntu-standard:amd64 (1.404, 1.404.1), gir1.2-accountsservice-1.0:amd64 (0.6.42-0ubuntu3, 0.6.42-0ubuntu3.1), nodejs:amd64 (6.11.5-1nodesource1, 6.12.0-1nodesource1), ubuntu-session:amd64 (3.26.1-0ubuntu5, 3.26.1-0ubuntu6), ubuntu-desktop:amd64 (1.404, 1.404.1), cups-server-common:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), xdg-utils:amd64 (1.1.1-1ubuntu2, 1.1.1-1ubuntu3), gdm3:amd64 (3.26.1-3ubuntu2, 3.26.1-3ubuntu3), cups-common:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), libapt-pkg5.0:amd64 (1.5, 1.5.1), linux-signed-generic:amd64 (4.13.0.16.17, 4.13.0.17.18), gir1.2-gdm-1.0:amd64 (3.26.1-3ubuntu2, 3.26.1-3ubuntu3), mutter-common:amd64 (3.26.1-2ubuntu1, 3.26.2-0ubuntu0.1), samba-libs:amd64 (2:4.6.7+dfsg-1ubuntu3, 2:4.6.7+dfsg-1ubuntu3.1), ubuntu-minimal:amd64 (1.404, 1.404.1), apport:amd64 (2.20.7-0ubuntu3, 2.20.7-0ubuntu3.5), libgdm1:amd64 (3.26.1-3ubuntu2, 3.26.1-3ubuntu3), libsane1:amd64 (1.0.27-1~experimental2ubuntu1, 1.0.27-1~experimental2ubuntu2.1), libgtk-3-bin:amd64 (3.22.24-0ubuntu1, 3.22.25-0ubuntu0.1), python3-distupgrade:amd64 (1:17.10.7, 1:17.10.8), cups-ppdc:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), libcupsmime1:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), chromium-browser:amd64 (62.0.3202.89-0ubuntu0.17.10.1386, 62.0.3202.94-0ubuntu0.17.10.1388), ubuntu-release-upgrader-core:amd64 (1:17.10.7, 1:17.10.8), python3-apport:amd64 (2.20.7-0ubuntu3, 2.20.7-0ubuntu3.5), libgtk-3-dev:amd64 (3.22.24-0ubuntu1, 3.22.25-0ubuntu0.1), firefox-locale-en:amd64 (56.0+build6-0ubuntu1, 57.0+build4-0ubuntu0.17.10.5), firefox-locale-es:amd64 (56.0+build6-0ubuntu1, 57.0+build4-0ubuntu0.17.10.5), chromium-codecs-ffmpeg-extra:amd64 (62.0.3202.89-0ubuntu0.17.10.1386, 62.0.3202.94-0ubuntu0.17.10.1388), gnome-shell-common:amd64 (3.26.1-0ubuntu4, 3.26.1-0ubuntu5), libgail-3-0:amd64 (3.22.24-0ubuntu1, 3.22.25-0ubuntu0.1), distro-info-data:amd64 (0.36, 0.36ubuntu0.1), libwebkit2gtk-4.0-37:amd64 (2.18.0-2, 2.18.3-0ubuntu0.17.10.1), gnome-shell-extension-appindicator:amd64 (17.10.1, 17.10.2), apt-utils:amd64 (1.5, 1.5.1), libsmbclient:amd64 (2:4.6.7+dfsg-1ubuntu3, 2:4.6.7+dfsg-1ubuntu3.1), gnome-session-bin:amd64 (3.26.1-0ubuntu5, 3.26.1-0ubuntu6), gnome-characters:amd64 (3.26.1-1, 3.26.2-0ubuntu1), gnome-control-center-faces:amd64 (1:3.26.1-0ubuntu4, 1:3.26.1-0ubuntu5), apport-gtk:amd64 (2.20.7-0ubuntu3, 2.20.7-0ubuntu3.5), ubuntu-release-upgrader-gtk:amd64 (1:17.10.7, 1:17.10.8), libsane-common:amd64 (1.0.27-1~experimental2ubuntu1, 1.0.27-1~experimental2ubuntu2.1), libcupsppdc1:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), gir1.2-webkit2-4.0:amd64 (2.18.0-2, 2.18.3-0ubuntu0.17.10.1), firefox:amd64 (56.0+build6-0ubuntu1, 57.0+build4-0ubuntu0.17.10.5), gnome-shell:amd64 (3.26.1-0ubuntu4, 3.26.1-0ubuntu5), cups-bsd:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), apt-transport-https:amd64 (1.5, 1.5.1), gtk-update-icon-cache:amd64 (3.22.24-0ubuntu1, 3.22.25-0ubuntu0.1), cups-core-drivers:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), cups-daemon:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), accountsservice:amd64 (0.6.42-0ubuntu3, 0.6.42-0ubuntu3.1), language-selector-gnome:amd64 (0.180, 0.180.1), chromium-browser-l10n:amd64 (62.0.3202.89-0ubuntu0.17.10.1386, 62.0.3202.94-0ubuntu0.17.10.1388), libcupsimage2:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), cups:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), libcupscgi1:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), cups-client:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), libjavascriptcoregtk-4.0-18:amd64 (2.18.0-2, 2.18.3-0ubuntu0.17.10.1), cups-ipp-utils:amd64 (2.2.4-7ubuntu2, 2.2.4-7ubuntu3), linux-generic:amd64 (4.13.0.16.17, 4.13.0.17.18), python3-problem-report:amd64 (2.20.7-0ubuntu3, 2.20.7-0ubuntu3.5), libaccountsservice0:amd64 (0.6.42-0ubuntu3, 0.6.42-0ubuntu3.1), gir1.2-javascriptcoregtk-4.0:amd64 (2.18.0-2, 2.18.3-0ubuntu0.17.10.1), mutter:amd64 (3.26.1-2ubuntu1, 3.26.2-0ubuntu0.1), gnome-shell-extension-ubuntu-dock:amd64 (0.7, 0.7.1), indicator-printers:amd64 (0.1.7+17.04.20170227-0ubuntu3, 0.1.7+17.10.20171021-0ubuntu1)
End-Date: 2017-11-27 09:03:07
lightdm 有问题。我换成了 gm3，现在它可以正常工作了。仍然无法将设备与蓝牙配对，但我会为此开另一个帖子。