xmonad.hs:401:43: warning: [-Wdeprecations]
    In the use of ‘spacing’ (imported from XMonad.Layout.Spacing):
    Deprecated: "Use spacingRaw instead."
    |
401 | addSpace     = renamed [CutWordsLeft 2] . spacing gap
    |                                           ^^^^^^^

xmonad.hs:459:1: warning: [-Wtabs]
    Tab character found here, and in 10 further locations.
    Please use spaces instead.
    |
459 |         , className =? "thunderbird"    --> doShift "9: mail"
    | ^^^^^^^^