Chinese input method on Linux + GNOME Wayland (fcitx5 + Rime/雾凇)

Battle-tested on Ubuntu 24.04, GNOME, Wayland, installed from scratch and verified working. Adapt version numbers to your distro.

In one line: fcitx5 (framework) + Rime/雾凇拼音 rime-ice (the open-source setup closest to Sogou's feel) + mellow theme (modern rounded corners). Fully local, no flicker, no privacy upload.

When and why to use this

GNOME deliberately integrates only ibus natively and does not speak the Wayland input-method protocol for third-party IMEs. Two consequences drive this whole guide:

• Sogou (搜狗) on Linux is still fcitx4. Under GNOME Wayland its candidate window flickers endlessly and you can't type. It's closed-source and can't be ported to fcitx5. Don't install fcitx4 Sogou on Wayland.
• fcitx5 + Rime is the most practical, stable replacement. It works for the vast majority of GTK/Qt apps via the IM modules (no flicker, far better than fcitx4), and Rime + 雾凇 (rime-ice) is the closest open-source feel to Sogou.

If the user insists on Sogou specifically, the only working path is to log into an Xorg session instead of Wayland (see the rollback/alternatives notes at the end and references/install-walkthrough.md).

Target environment

Steps

Follow these in order. The full, annotated walkthrough with every gotcha is in references/install-walkthrough.md — read it if a step misbehaves. For styling the candidate popup, see references/kimpanel-theming.md.

1. Install the fcitx5 stack

sudo apt update
sudo apt install -y \
  fcitx5 fcitx5-chinese-addons fcitx5-config-qt \
  fcitx5-frontend-gtk3 fcitx5-frontend-gtk4 fcitx5-frontend-qt5 \
  fcitx5-material-color

Switch the default IM framework to fcitx5:

im-config -n fcitx5      # writes ~/.xinputrc as: run_im fcitx5

2. Environment variables (⚠️ the #1 gotcha: the value is fcitx, NOT fcitx5)

fcitx5's Qt/GTK plugins still register under the name fcitx (the Qt class is fcitx::QFcitxPlatformInputContext). Writing fcitx5 makes Qt apps unable to type. fcitx5-diagnose will warn about this explicitly.

# Clear any stale values first, then write
sudo sed -i '/^GTK_IM_MODULE=/d;/^QT_IM_MODULE=/d;/^XMODIFIERS=/d' /etc/environment
sudo tee -a /etc/environment >/dev/null <<'EOF'
GTK_IM_MODULE=fcitx
QT_IM_MODULE=fcitx
XMODIFIERS=@im=fcitx
EOF

On GNOME Wayland, Qt5/XWayland apps need these variables. GTK apps could use native text-input-v3, but keeping a global GTK_IM_MODULE=fcitx is the most universal, hassle-free choice.

3. Autostart

GNOME Wayland does not run ~/.xinputrc; use an XDG autostart entry instead:

mkdir -p ~/.config/autostart
cat > ~/.config/autostart/fcitx5.desktop <<'EOF'
[Desktop Entry]
Type=Application
Name=Fcitx5
Exec=fcitx5 -d
Icon=fcitx
Terminal=false
X-GNOME-Autostart-enabled=true
EOF

4. (Optional) Default pinyin engine settings

Skip this entire step if you only use Rime/雾凇 (recommended). It's only for keeping fcitx5's built-in pinyin around for comparison.

Cloud pinyin via Baidu (Google's endpoint often times out in mainland China):

mkdir -p ~/.config/fcitx5/conf
cat > ~/.config/fcitx5/conf/cloudpinyin.conf <<'EOF'
Backend=Baidu
MinimumPinyinLength=4
EOF

fcitx5's candidate count maxes out at 10 — set PageSize=10 in ~/.config/fcitx5/conf/pinyin.conf (that file is generated after the first run).

5. Rime + 雾凇拼音 (the core)

5.1 Install the engine

sudo apt install -y fcitx5-rime

Pulls in the key plugins: librime-plugin-lua (雾凇 Lua features) and librime-plugin-octagram (whole-sentence grammar model). librime 1.10 is compatible with 雾凇 with no errors.

5.2 Fetch the 雾凇 (rime-ice) config

git clone --depth 1 https://github.com/iDvel/rime-ice.git /tmp/rime-ice
mkdir -p ~/.local/share/fcitx5/rime
cp -r /tmp/rime-ice/* ~/.local/share/fcitx5/rime/

5.3 Set Rime's candidate count to 10 (Rime's count is independent of fcitx5; 雾凇 defaults to 5):

cat > ~/.local/share/fcitx5/rime/default.custom.yaml <<'EOF'
patch:
  menu/page_size: 10
EOF

5.4 Deploy (compiles hundreds of thousands of entries; first run is slow):

rime_deployer --build ~/.local/share/fcitx5/rime /usr/share/rime-data

Success marker: ~/.local/share/fcitx5/rime/build/rime_ice.table.bin (~58 MB) and friends are generated with no errors.

5.5 Add Rime to the input-method group

Edit ~/.config/fcitx5/profile: put rime first, followed by keyboard-us, and do not include fcitx5's built-in pinyin (mixing them makes different apps remember different engines and show two candidate sets). Set DefaultIM=rime. Minimal template:

[Groups/0]
Name="Default"
Default Layout=us
DefaultIM=rime

[Groups/0/Items/0]
Name=rime
Layout=

[Groups/0/Items/1]
Name=keyboard-us
Layout=

[GroupOrder]
0="Default"

⚠️ pkill -9 fcitx5 before editing profile, otherwise fcitx5 overwrites the file from its in-memory config on exit. Then restart: fcitx5 -d.

6. Theme (modern rounded corners, optional)

git clone --depth 1 https://github.com/sanweiya/fcitx5-mellow-themes.git /tmp/mellow
mkdir -p ~/.local/share/fcitx5/themes
cp -r /tmp/mellow/mellow-* ~/.local/share/fcitx5/themes/   # opaque variant for GNOME

Set theme + font in ~/.config/fcitx5/conf/classicui.conf:

Vertical Candidate List=False
WheelForPaging=True
Font="Sans 11"
PerScreenDPI=True
Theme=mellow-wechat

Palettes: mellow-{youlan|sakura|vermilion|wechat|graphite}, each with a -dark variant. For deeper customization of the candidate popup (especially the flicker fix via kimpanel), see references/kimpanel-theming.md.

7. Finish & verify

fcitx5-remote -r            # reload config (or pkill -9 fcitx5 then fcitx5 -d)
fcitx5-diagnose | less      # self-check: env vars, frontends

• Toggle IME: Ctrl+Space. Switch Rime schema (雾凇/double-pinyin/etc.): Ctrl+` (backtick).
• Verify whole-sentence 雾凇: type a long unsegmented string like jintiantianqibucuo → it should produce「今天天气不错」.
• In the IME list Rime shows as「中州韵 / Rime」, default schema「雾凇拼音」.

⚠️ Must do: log out and back in

The /etc/environment variables only take full global effect after a re-login. Log out → log back in once after installing.

Common pitfalls

1. Env-var value is fcitx, not fcitx5 (Step 2) — the most common mistake; gets it wrong and Qt apps can't type.
2. pkill fcitx5 before editing profile (Step 5.5), or it gets overwritten by the in-memory config.
3. Don't click "Apply" in an old fcitx5-configtool window — it may overwrite the profile you just edited. Reopen a fresh one.
4. Rime's candidate count and fcitx5 pinyin's PageSize are two separate settings — patch Rime via default.custom.yaml (Step 5.3).
5. No real frosted-glass blur on GNOME (the compositor won't blur third-party IME popups) — use an opaque theme.
6. Candidate window occasionally mis-positioned / flickering in native Wayland apps (e.g. the terminal) — install the Kimpanel GNOME extension to fix it root-and-branch. See references/kimpanel-theming.md. Not required.
7. Inconsistent skin/engine across apps — fcitx5 renders candidates on two paths (X11/XWayland vs Wayland); a hot reload may refresh only one. pkill -9 fcitx5 + restart unifies them (and a re-login prevents it entirely). Also, with both 雾凇 and pinyin in the group, apps remember different engines — so this guide uses 雾凇 only.

Rollback (back to ibus)

im-config -n ibus
sudo sed -i '/^GTK_IM_MODULE=/d;/^QT_IM_MODULE=/d;/^XMODIFIERS=/d' /etc/environment
rm -f ~/.config/autostart/fcitx5.desktop
# Full uninst