Hi Pelle, I can't reproduce this error on my swayfx machine.
I have |exec_always swaync |in my swayfx config and running |notify-send "hello world" |works just fine.
That is with sway-nc 0.9.0-1 and swayfx 0.3.2. I'll retest with the latest sway; just to make sure.
best, werdahias
