The defvar do not take effect in defwindow.

[DoubleBobCat]

Here are part of my eww.yuck configure

; ----- var -----
;; common
(defvar BAR_HEIGHT "30px")

; ----- windows -----
(defwindow win0 :monitor 0
               :geometry (geometry :x 0 :y 0 :height BAR_HEIGHT :width "100%" :anchor "center top")
               :stacking "fg" 
               :exclusive true
               :focusable false
  (bar0 :monitor "eDP-1")
)

After run eww --restart daemon and eww open win0
It shown this error:

failed to open window `win0`

Caused by:
    Unknown variable BAR_HEIGHT

But why?