（4.13.16-300.fc27.x86_64 --> 4.14.13-300.fc27.x86_64）
升级 Fedora 27 （dnf update）后 ，输入法失效。
问题解决思路，找到需要 降级 的软件包。
具体命令：
dnf groupinfo "Input Methods"
dnf downgrade ibus-cangjie-engine-cangjie ibus-hangul ibus-kkc ibus-libpinyin ibus-libzhuyin ibus-m17n ibus-rawcode ibus-typing-booster im-chooser imsettings WritRecogn cellwriter eekboard fcitx gcin ibus-anthy ibus-bogo ibus-cangjie-engine-quick ibus-fbterm ibus-gucharmap ibus-handwrite ibus-input-pad ibus-mozc ibus-sayura ibus-skk ibus-table ibus-table-array30 ibus-table-cyrillic ibus-xkbc input-pad iok kinput2 scim-anthy scim-array scim-bridge-gtk scim-bridge-qt scim-bridge-qt3 scim-chewing scim-fcitx scim-gtk scim-hangul scim-m17n scim-pinyin scim-rawcode scim-sayura scim-tables-additional scim-tables-chinese scim-tables-chinese-extra scim-thai uim uim-anthy uim-canna uim-gtk2 uim-gtk3 uim-m17n uim-qt3 uim-skk gtk2-immodule-xim gtk3-immodule-xim ibus-gtk2 ibus-gtk3 ibus-qt im-chooser-xfce imsettings-cinnamon imsettings-gsettings imsettings-lxde imsettings-mate imsettings-qt imsettings-xfce
reboot
输入法失效时，错误信息如下：
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cat /root/.cache/imsettings/log
====================================================================
[ 1516288263.533650]: IMSettings-Daemon[1785]: INFO: Starting imsettings-daemon...
[ 1516288263.534067]: IMSettings-Daemon[1785]: INFO: [HOME=/root/.config/imsettings]
[ 1516288263.534084]: IMSettings-Daemon[1785]: INFO: [XINPUTRCDIR=/etc/X11/xinit/]
[ 1516288263.534097]: IMSettings-Daemon[1785]: INFO: [XINPUTDIR=/etc/X11/xinit/xinput.d/]
[ 1516288263.534109]: IMSettings-Daemon[1785]: INFO: [MODULEDIR=/usr/lib64/imsettings]
[ 1516288263.534121]: IMSettings-Daemon[1785]: INFO: [MODULES=gsettings, qt]
imsettings information
==========================
XINPUTRC: /root/.config/imsettings/xinputrc
文件：/root/.config/imsettings/xinputrc -> /etc/X11/xinit/xinput.d/fcitx.conf
大小：34 块：0 IO 块：4096 符号链接
设备：805h/2053d Inode：2232596 硬链接：1
权限：(0777/lrwxrwxrwx) Uid：( 0/ root) Gid：( 0/ root)
环境：unconfined_u:object_r:config_home_t:s0
最近访问：2018-01-18 14:20:36.609461488 +0800
最近更改：2017-11-17 14:13:52.047637859 +0800
最近改动：2017-11-17 14:13:52.048637859 +0800
创建时间：-
Is DBus enabled: yes
Is imsettings enabled: yes
Is GTK+ supported: yes
Is Qt supported: yes
DESKTOP: GNOME-Classic:GNOME
GUESS_DESKTOP: $XDG_CURRENT_DESKTOP
DISABLE_IMSETTINGS:
IMSETTINGS_DISABLE_DESKTOP_CHECK:
DBUS_SESSION_BUS_ADDRESS: unix:path=/run/user/0/bus
GTK_IM_MODULE:
QT_IM_MODULE: xim
XMODIFIERS: @im=fcitx
IMSETTINGS_MODULE: FCITX
IMSETTINGS_INTEGRATE_DESKTOP: yes
[ 1516288271.441415]: IMSettings-Daemon[1785]: INFO: Attempting to switch IM to FCITX [lang=zh_CN.UTF-8, desktop=GNOME-Classic_GNOME, update=false]
org.gnome.SettingsDaemon.Keyboard.desktop exists. imsettings is going to be disabled.
[ 1516288271.997997]: IMSettings-Daemon[1785]: WARNING **: Current desktop isn't targeted by IMSettings.
[ 1516288272.002631]: IMSettings-Daemon[1785]: INFO: Unloading imesttings module: qt
[ 1516288272.002762]: IMSettings-Daemon[1785]: INFO: Unloading imesttings module: gsettings
[ 1516288272.002821]: IMSettings-Daemon[1785]: INFO: imsettings-daemon is shut down.
[ 1516288295.851391]: IMSettings-Daemon[2808]: INFO: Starting imsettings-daemon...
[ 1516288295.851493]: IMSettings-Daemon[2808]: INFO: [HOME=/root/.config/imsettings]
[ 1516288295.851533]: IMSettings-Daemon[2808]: INFO: [XINPUTRCDIR=/etc/X11/xinit/]
[ 1516288295.851555]: IMSettings-Daemon[2808]: INFO: [XINPUTDIR=/etc/X11/xinit/xinput.d/]
[ 1516288295.851573]: IMSettings-Daemon[2808]: INFO: [MODULEDIR=/usr/lib64/imsettings]
[ 1516288295.851591]: IMSettings-Daemon[2808]: INFO: [MODULES=gsettings, qt]
[ 1516288318.141904]: IMSettings-Daemon[2808]: INFO: Attempting to switch IM to FCITX [lang=zh_CN.UTF-8, desktop=(null), update=true]
org.gnome.SettingsDaemon.Keyboard.desktop exists. imsettings is going to be disabled.
[ 1516288318.300829]: IMSettings-Daemon[2808]: WARNING **: Current desktop isn't targeted by IMSettings.
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