Visual problems after updating to Ubuntu 21.10
Output of awesome --version:
awesome v4.3-1220-g1d55ae09 (Too long)
• Compiled against Lua 5.3.3 (running with Lua 5.3)
• API level: 4
• D-Bus support: yes
• xcb-errors support: no
• execinfo support: yes
• xcb-randr version: 1.6
• LGI version: 0.9.2
• Transparency enabled: yes
• Custom search paths: no
How to reproduce the issue:
I recently updated Ubuntu from 21.04 to 21.10, and tried to compile AwesomeWM for the first time.
Actual result:
Wiboxes doesn't seem to work as expected:
- Buttons dissapears
- Inverted shapes
- Icons with weird sizes
This is a screenshot of how it looks:

And here a video demonstrating the result: https://streamable.com/87vdw8
Expected result:
- Powerline shapes should point the other way around
- Left buttons on wibar shouldn't dissapear
Screenshot before updating (months ago):

I guess this may be related to dependency conflicts. Also, tried to recompile with Lua3.1, Lua3.3, LuaJIT, and remove/install with apt, but the problem persists.
Hello,
Looks like you have a compositing manager like picom running. Can you confirm it works fine when you disable it? If so, the problem is there.
Otherwise, the version ubuntu ships hasn't changed in a few years, so this isn't due to a new feature
Yep, I'm using Picom, but disabling it just makes transparent things to be black. Nothing related.
Although, AwesomeWM was working fine after updating. The problem came when I compiled it, but no errors or warnings. So, idk where the problem could be.
Can you bisect which commit causes the regression? (that means recompiling some random commits between the point where it works and the point where it doesn't. git bisect and Xephyr helps with that).
Tried bisect and compile: 70cd2938 was the first one that didn't crash, but the problem is still there. Newer commits work the same... I'm starting to think the problem is Ubuntu.

does it happen when you start awesome with --no-argb flag?
No, sadly, using that flag didn't work.
However, it seemed to be some kind of incompatibility of my rc.lua and theme.lua with the current AwesomeWM version. I still don't know why this happened, but I managed to fix it.
Some flipped gear.shapes functions were not working as they did previously:
local flipped_arrow = function(cr, width, height)
cr:translate(width, height)
cr:rotate(math.pi)
gears.shape.rectangular_tag(cr, width, height)
end
And now they work:
local flipped_arrow = function(cr, width, height)
local shape = gears.shape.transform(gears.shape.rectangular_tag)
:translate(width, height)
:rotate(math.pi)
shape(cr, width, height)
end

(Weird icon sizes on right "taskbar" are still being a problem, but I'll see how to fix them.)
Do you have a minimal example rc.lua which can reproduce the problem. I am still interested in getting to the bottom of this. We try to make the releases backward compatible. Obviously, the more elaborate the config is, the more likely it rely in undefined/undocumented behaviors and/or private APIs. But that doesn't look like to be the case if the change you posted ended up fixing the problem.
Well, this would be a minimal config of mine: see this gist
And here are the problematic functions: see here