neovide: Unable to trigger fcitx5 when using neovide

Describe the bug The fcitx5 App is an input method engine that I use for input Chinese. It works on most of my desktop applications like Neovim-QT, Telegram, and Firefox…etc. I recently switched to use neovide. It meets my needs very well, except for one thing: I can’t use the hotkey to trigger the input method.

I am using <CTRL>+<SHIFT> and <CTRL>+<SPACE> to trigger my fcitx5. When I press <CTRL>+<SPACE>, it triggers the inner completion menu, and when I press <CTRL>+<SHIFT>, nothing happens.

It’s weird because whatever the hotkey I used, the nvim-qt can work as expected, so maybe it is not my neovim configuration error. Moreover, no error report from fcitx5-diagnose, so maybe it is not my fcitx5 configuration error.

But I can’t find any issues related to fcitx5, so I am here to ask for help.

To Reproduce Steps to reproduce the behavior:

1. Install packages fcitx5, fcitx5-im, fcitx5-rime
2. Set environment variable like below:

export GTK_IM_MODULE=fcitx
export QT_IM_MODULE=fcitx
export QT4_IM_MODULE=fcitx
export XMODIFIERS=@im=fcitx
export SDL_IM_MODULE=fcitx
export INPUT_METHOD=fcitx

1. Run fcitx-configtool and add rime below the Keyboard-English

1. Set hotkey like below

1. Open neovide and try to press those hotkey

Expected behavior

The behavior I expect is like nvim-qt. I’ve recorded a video to show the difference.

https://user-images.githubusercontent.com/30021675/136696662-a735b535-f87e-4fad-9248-a638e9839233.mp4

Desktop (please complete the following information):

• OS: Linux 5.14.9-arch
• Neovide Version: Neovide 0.8.0 from neovide-git
• Neovim Version [e.g. 0.5.0]: NVIM v0.6.0-dev+132-g7d2233fad

Please run neovide --log and paste the contents of the .log file here:

Log:

TRACE [neovide] Neovide version: 0.8.0

Additional context My rime settings: https://github.com/Avimitin/rime My NeoVIM settings: https://github.com/Avimitin/nvim fcitx5 diagnose output: https://pastebin.com/QQ0tERtZ