Subject: bug#40047: 26.2; Images in tooltip-mode tooltips broken on Linux and OSX

From: Eli Zaretskii <[email-masked]>
Date: Fri, 13 Mar 2020 10:18:06 +0200

> From: Dustin Lacewell <[email-masked]>
> Date: Thu, 12 Mar 2020 16:54:26 -0500
> 
> Just `eval-buffer` then hover your mouse over `Facepalm` in the new
> buffer.
> 
> Emacs versions 26.2 26.3 and 28.0.50 were tested on NixOS, Ubuntu, OSX
> and Windows.
> 
> On Windows a tooltip displays an image. On Linux (NixOS, Ubuntu) and OSX
> only a small empty tooltip is presented.

If, in the GNU/Linux build, you set x-gtk-use-system-tooltips to nil,
does the problem go away?