While running drawterm under sway (wayland), the middle mouse button triggered both down and up only *after* the button was released (as seen by xev).
It came down to 'button scrolling' on the TrackPoint device (you can hold the middle button and scroll with the trackpoint). I couldn't figure out how to get libinput to stop doing this.
With a nudge from @sigrid@merveilles.town toward sway-input and it's man page. I added the following to my sway config:
input * scroll_button disable
@feoh I am running sway on a Linux machine and using drawterm to connect to my Plan9 box.
@nocko Plan-9 has some incredible ideas in there. I sometimes think that as awesome as the UNIX paradigm is, people have somewhat stopped innovating because so many things Just Work and there's no impetus to improve them.
@nocko You're running Wayland/Sway on Plan-9? My god man, you're on the bleeding edge of the bleeding edge :)