> > You need to enable that with "resize" and "drag".
>
> I've done that, but it's very possible I'm overlooking something or my
> environment is quirky. I've tried opening vim in/out of tmux, with/out a
> .vimrc and almost every variation of the optional configs I can think of.
> I'm using Debian 10, i3 version 4.16.1 and vim patch 8.1.1944.
>
> Here's a screencap of the behavior I see:
>
https://www.dropbox.com/s/ooc18fc0hmzi5ej/vim-popup-resize-drag.ogv?dl=0
The command is right, and it works for me. Thus there is something wrong
with mouse events in your setup. Probably drag events don't work.
I have seen that with some terminal emulators.
--
Some of the well known MS-Windows errors:
EHUH Unexpected error
EUSER User error, not our fault!
EGOD Horrible problem, god knows what has happened
EERR Errornous error: nothing wrong