Hi there!

Since the upstreaming of the Input Portal changes in KDE Plasma 6.1, I decided to test out Input Leap with my Fedora 40 Server and MacOS client setup. Spoilers: I did get it to work, but there were some extra steps and some pieces i want to share. This is a bit of a step-by-step of what I did and why, and then in a later section I have what is/"isn't" working.

Preface

My primary driver is a Fedora 40 Workstation desktop. I utilize Wayland as my default environment now, via Plasma. I am running an Nvidia GPU (because even in places where that doesn't matter, it somehow matters). My client device is an M3 Pro MacBook.

I wanted to stop using a (poor) physical USB KVM since the MacBook wouldn't properly send reinitialize signals for USB devices.

The rpm packaged by the GH Action tries to run the server through XWayland, which didn't work for me, which led me to building it locally.

Building

Dependencies

For Fedora 40, the following dependencies are also necessary: qt6-qtbase qt6-qtbase-devel qt6-qttools-devel.

CMake

There are two relevant CMake flags: INPUTLEAP_BUILD_LIBEI and INPUTLEAP_BUILD_X11. My first inclination was to build without X11, but that doesn't work right now. I added it as an extra line in the clean_build.sh build script:

...
B_CMAKE_FLAGS="-DINPUTLEAP_BUILD_LIBEI=ON"
B_BUILD_DIR ...

Running the build at this point succeeded. But, when running it, I get the following error in the logs:

[timestamp] FATAL: An error occurred: Missing libportal InputCapture portal support
	.../input-leap/src/lib/inputleap/App.cpp,115

libportal

On Fedora, libportal's version is 0.7.1-3.fc40. Version 0.8.x released with support for the Input Capture portal, but that was only at the beginning of September. You can see that it's not even in Rawhide yet (as of writing). This upstream issue is tracking that the update is available, for Red Hat. (Also of note, I'm not sure that's the exact thing that was released that fixed later issues, but the newer version works and the older one didn't. Could be qt6, since I don't have libportal-qt6 on my machine or available at all in the Fedora repos.)

So, the "clear" solution is to download and build it. I found this thread where Benny Powers described their process of building input-leap from scratch. An additional dependency I needed was vala for vapigen, and the important part here is meson _build, ninja -C _build, and cd _build && sudo meson install.

Then, you can go back and re-run the build for input-leap.

Running

So, success, right?

Actually, yes. At this point, running the server properly prompted me to allow something to have control (the portal support), and I was able to connect to the server from my MacBook.

Bugs and Oddities

Server (Fedora)

• When moving the mouse down on a client toward the bottom of the screen, KDE will treat it as a hovering event over the different windows in the docking bar or whatever it's called these days.
• "Shaking" the mouse around while on a client will have the KDE "mouse cursor growing" effect on the server.

Client (MacOS)

• Scrolling with my mouse sends a single scroll "notch" and then ignores / eats any additional scroll events.
• Leaving the mouse idle for too long on the Client "resets" it to the host screens.
• If the mouse idles, it seems to briefly "freeze" before catching up to whatever movement is made. Looks similar to [Bug] Mouse is jumping #300, including the part where if you down the awdl0 interface, the performance improves. Also you only get that for a second or so because it'll immediately "restart."
• The freeze aspect seems to hold for the keyboard, as well, as there will be times where it takes a second or so for it to "catch" up to what you've typed. Sometimes this eats inputs.