awesome v4.0 (Harder, Better, Faster, Stronger)
• Compiled against Lua 5.1.5 (running with Lua 5.1)
• D-Bus support: ✔
• execinfo support: ✔
• RandR 1.5 support: ✔
• LGI version: 0.9.1

Using the quake util via the following in my rc.lua

local lain = require("lain")
…
awful.screen.connect_for_each_screen(function(s)
…
    s.quake = lain.util.quake()
end)

The key shortcut hook:

globalkeys = awful.util.table.join(
…
    awful.key({ modkey }, "`", function () awful.screen.focused().quake:toggle() end)
)

On occasion, rather than show or hide the terminal (which is defaulting to xterm), I get a pop-up error message Oops, an error has happened! /usr/share/awesome/lib/awful/client.lua:1060: invalid object

This happens after I've added or removed an external display. For example, just now, I've added an external display, used the key shortcut to show the quake terminal (which worked, and displayed on my external display) but the same key shortcut immediately afterwards to hide it failed. Exiting the terminal and trying the key shortcut causes the error too (no more quake console for me until I restart awesome)

Interestingly, if I switch focus to my laptop display, the key shortcut is spawning an xterm, but it is not placing it in the right place (it's being tiled like a normal window), the shortcut is not hiding it again, anda subsequent (3rd, 5th, 7th, etc.) press of the shortcut spawns a second (3rd, 4th..) xterm. No errors displays for this sequence of events.

my rc.lua is an otherwise almost unmodified copy of /etc/xdg/awesome/rc.lua from the debian package.